Cause and Origin Fire Investigations: What Policyholders Need to Know

After a fire, one of the first things that happens — often before you have even processed what you have lost — is a cause and origin investigation. Someone will be poking through the debris of your property trying to determine what started the fire and where it began. What many policyholders do not realize is that there are typically two entirely separate cause and origin investigations happening, conducted by different entities with very different motivations. Understanding the difference between these investigations, what your rights are during each, and how the findings can affect your insurance claim is critical to protecting yourself.

The Fire Department Cause & Origin Investigation

When the fire department responds to a structure fire, one of its duties is to investigate the cause and origin of the fire. This investigation is conducted by fire department investigators — sometimes called fire marshals or arson investigators — who are public servants working for a government agency. Their primary concern is straightforward: Was this arson? Was a crime committed?

The fire department's investigation is a criminal investigation. The investigator is looking for evidence of intentional fire-setting: accelerant use, multiple points of origin, evidence of forced entry, or other indicators of an incendiary fire. If the investigation determines the fire was deliberately set, the case is referred to law enforcement for potential criminal prosecution.

What the fire department is nottypically focused on is whether a manufacturer's defect caused the fire, whether a contractor performed faulty electrical work, or whether a specific appliance malfunctioned. Those questions are simply outside their jurisdiction. If the fire department determines the fire was not arson — that it was accidental — their investigation is essentially complete. They will document their findings in a fire incident report, assign a cause classification (electrical, cooking, heating equipment, etc.), and move on. They are not in the business of identifying responsible third parties or determining who might be liable in a civil context.

Fire department investigators are required to follow the scientific methodology outlined in NFPA 921, Guide for Fire and Explosion Investigations, and to meet the professional qualifications established by NFPA 1033, Standard for Professional Qualifications for Fire Investigator. In California, fire investigators employed by fire departments are typically peace officers under Penal Code § 830.37, which gives them authority to investigate arson and issue subpoenas for records.

What the Fire Department Report Tells You — and What It Doesn't

The fire department's incident report will typically include the date, time, and location of the fire; the area of origin; the suspected cause (or “undetermined” if the evidence was insufficient); and whether the fire is classified as accidental, incendiary, natural, or undetermined. This report is a public record and you are entitled to a copy.

What the fire department report will generally nottell you is who manufactured the appliance that malfunctioned, whether the electrical wiring met code, or whether a specific contractor's work contributed to the fire. Those are questions for a different type of investigation — and that is where the insurance company comes in.

The Insurance Company's Cause & Origin Investigation

After a significant fire loss, the insurance company will almost always retain its own cause and origin investigator — a private fire investigator, often a former fire department investigator or an engineer specializing in fire forensics. This investigator works for the insurance company (or a firm retained by the insurance company) and is paid by the insurance company. This is a fundamentally different investigation from the fire department's, and the difference in incentives is something every policyholder should understand clearly.

The insurance company's C&O investigator has a different focus than the fire department. While the fire department asks, “Was this a crime?” the insurance company asks, “Is there a third party we can subrogate against?” Was there a manufacturer's defect in an appliance, a piece of equipment, or an electrical component? Did a contractor perform faulty wiring? Was there a product that failed? In other words, the insurance company is looking for someone — other than the policyholder — to blame for the fire, because if it can identify a responsible third party, it can pursue subrogation to recover the money it pays out on the claim.

What the Insurance Company's Investigation Is Really Looking For

• Product defects. Was there a defective appliance, electrical panel, HVAC unit, battery, or other product at the point of origin? If so, the manufacturer or distributor may be a subrogation target under strict product liability.
• Contractor or workmanship failures.Was electrical work recently performed at the property? Was the wiring up to code? Did a contractor install something improperly? If faulty workmanship caused or contributed to the fire, the contractor — and the contractor's insurance — may be a recovery target.
• Utility company responsibility.Did a power surge or equipment failure on the utility company's infrastructure cause the fire? Utility-caused fires are a significant source of subrogation recovery.
• Neighbor or third-party negligence.Did the fire originate on a neighboring property due to someone else's negligence? If so, the neighbor and the neighbor's liability insurance become subrogation targets.
• Arson by a third party. If the fire was intentionally set by someone other than the policyholder, that person is both criminally liable and civilly liable. The insurer may pursue the arsonist for recovery.

When the Investigation Is Also Looking at the Policyholder

It would be incomplete to discuss the insurance company's C&O investigation without acknowledging that in some cases, the insurer is also investigating whether the policyholder caused or contributed to the fire — whether through arson, negligence, or misrepresentation. If the insurer suspects policyholder involvement, the C&O investigation may overlap with or be coordinated with the carrier's Special Investigations Unit (SIU). If this is happening on your claim, you need an attorney. See our discussion of recorded statements and SIU for more on this topic.

NFPA 921: The Scientific Standard for Fire Investigation

Both fire department and private fire investigators are expected to follow NFPA 921, Guide for Fire and Explosion Investigations. This document, published by the National Fire Protection Association, is the recognized standard for fire investigation methodology in the United States. Courts routinely accept NFPA 921 as the authoritative guide for how fire investigations should be conducted, and expert testimony that departs from NFPA 921 methodology is frequently challenged under Daubert (federal) or the Kelly/Sargon framework (California).

NFPA 921 requires investigators to follow the scientific method: formulate a hypothesis based on the evidence, test the hypothesis against all available data, and eliminate hypotheses that are inconsistent with the facts. An investigator who reaches a conclusion without testing it against alternative hypotheses — or who selects a conclusion and then seeks evidence to support it — is not following NFPA 921.

This is important for policyholders because if the insurance company's investigator produces a report that does not follow NFPA 921 methodology, that report is subject to challenge. Common methodological failures include: reaching a cause determination without adequately ruling out alternative causes; relying on outdated “indicators” that NFPA 921 has debunked (such as certain burn pattern interpretations that were once erroneously associated with arson); and arriving at a cause determination when the evidence only supports an “undetermined” classification.

NFPA 1033: Investigator Qualifications

NFPA 1033, Standard for Professional Qualifications for Fire Investigator, establishes the minimum knowledge, skills, and abilities required for a person to perform fire investigations competently. This standard requires demonstrated knowledge of fire science, fire behavior, building construction, electrical systems, evidence collection and preservation, and the legal aspects of fire investigation. Not every person presented as a “fire investigator” by an insurance company meets NFPA 1033 qualifications, and challenging an investigator's qualifications is a legitimate and sometimes necessary step in disputing the insurer's conclusions.

Your Rights During a Cause & Origin Investigation

Policyholders have rights during the C&O process, and it is important to know them before the investigator shows up at what remains of your property.

The Duty to Cooperate — and Its Limits

Your insurance policy includes a cooperation clause requiring you to assist the insurer in its investigation of your claim. Under the California standard fire policy (Insurance Code § 2071) and most homeowner policies, this includes submitting to examination under oath, producing documents, and making the property available for inspection. The California Fair Claims Settlement Practices Regulations (10 CCR § 2695.7) also contemplate the insurer's right to conduct a reasonable investigation.

However, the duty to cooperate has limits. It does not require you to waive your legal rights. It does not require you to submit to unreasonable or oppressive demands. And critically, it does not require you to participate in the investigation without counsel.

The Right to Have Counsel Present

You have the right to have an attorney present during any interaction with the insurance company's investigator. This includes interviews, inspections, recorded statements, and examinations under oath. Exercising this right is not a breach of your duty to cooperate — it is the exercise of a fundamental legal protection. If the insurance company suggests otherwise, that suggestion itself may constitute a violation of California's Fair Claims Settlement Practices Act (Insurance Code §§ 790.03(h), 790.06) and the implementing regulations (10 CCR § 2695 et seq.).

You may also have your own public adjuster or forensic expert present during inspections. Having your own expert observe the insurance company's C&O investigation — examining the same evidence, taking independent photographs and samples, and documenting the investigation methodology — can be invaluable if you later need to challenge the insurer's conclusions.

Right to Obtain the Investigation Report

Under California's Fair Claims Settlement Practices Regulations (10 CCR § 2695.7(d)), you have the right to receive a written explanation of the basis for any claim decision. If the insurer is relying on its C&O investigation to deny, delay, or limit your claim, you are entitled to know what the investigation found. Additionally, under 10 CCR § 2695.7(b), the insurer must provide, upon request, all documents related to the evaluation of the claim, including expert reports. The insurer may resist providing the full C&O report, but under California law, you are entitled to the information the insurer relied on in making its coverage determination.

For a broader discussion of your right to see the documents in your claim file, see our article on the CDI's guidance on your right to claim documents.

Right to Retain Your Own Expert

You are not required to accept the insurance company's C&O findings as the final word. You have the right to retain your own fire investigation expert — a private fire investigator, a forensic engineer, or an electrical engineer — to conduct an independent analysis. If you believe the insurance company's investigation was flawed, biased, or reached conclusions unsupported by the evidence, your own expert can review the same evidence, test the insurer's hypotheses, and prepare an independent report. This is particularly important when the insurer's C&O findings form the basis for a denial or a coverage limitation. See our article on challenging insurance company engineering reports.

Scene Preservation: Why It Matters and Who Is Responsible

Preserving the fire scene is one of the most important — and most misunderstood — aspects of a fire claim. The physical evidence at the scene is the foundation for every cause and origin determination. Once that evidence is disturbed, destroyed, or removed, it may be impossible to determine the cause of the fire, to challenge the insurer's conclusions, or to pursue a subrogation claim against a responsible third party.

The Policyholder's Obligation

Your policy's duties after loss provisions require you to protect the property from further damage and to make it available for inspection. In the context of a fire, this means you should not authorize demolition, debris removal, or significant cleanup of the fire scene until all parties with an interest in the investigation have had an opportunity to examine it. This includes the fire department, your insurance company, and — if a subrogation claim may be involved — any third parties or their insurers.

At the same time, you have a duty to mitigate further damage. If the structure is at risk of collapse, if weather is threatening to damage what remains, or if there are safety hazards, you may need to take emergency protective measures. The key is to document everything before any work is done: photographs, video, written descriptions, and records of who authorized what work and when.

The Insurer's Obligation

The insurance company also has a responsibility with respect to scene preservation. Under California law, a party that has control over evidence relevant to litigation — or reasonably anticipated litigation — has a duty to preserve that evidence. If the insurer takes custody of items from the fire scene (appliances, electrical components, wiring samples), it must preserve them in a manner that allows for independent examination.

This obligation runs both ways. The insurer should not destroy or dispose of evidence that could be relevant to the policyholder's claim, just as the policyholder should not destroy or dispose of evidence that the insurer may need for its investigation or for subrogation purposes.

Spoliation of Evidence: A Serious Legal Issue

Spoliation is the destruction, alteration, or failure to preserve evidence that is relevant to pending or reasonably anticipated litigation. In the context of fire claims, spoliation issues arise frequently and can dramatically affect the outcome of a case.

California Law on Spoliation

California courts have addressed spoliation extensively. While California does not recognize an independent tort for spoliation of evidence by a party to litigation (Cedars-Sinai Medical Center v. Superior Court (1998) 18 Cal.4th 1; Temple Community Hospital v. Superior Court (1999) 20 Cal.4th 464), there are powerful remedies available when a party destroys or fails to preserve relevant evidence.

• Adverse inference instruction.If a party destroys evidence, the court may instruct the jury that it may presume the destroyed evidence was unfavorable to the party that destroyed it. Under California Evidence Code § 413, the trier of fact may draw an inference adverse to a party who willfully suppresses evidence. CACI Jury Instruction No. 204 provides the standard instruction for willful suppression of evidence.
• Issue sanctions or terminating sanctions.Under Code of Civil Procedure § 2023.030, a court may impose sanctions against a party that engages in spoliation, including issue sanctions (establishing certain facts as true), evidence sanctions (precluding the spoliating party from introducing evidence on the issue), or in extreme cases, terminating sanctions (striking pleadings or entering default).
• Separate tort against third parties. While California does not recognize a spoliation tort against litigation parties, third-party spoliation remains actionable under certain circumstances. If a non-party to the litigation destroys evidence, the affected party may have a claim for intentional interference with prospective economic advantage or negligence.

Spoliation in the Fire Claims Context

Spoliation problems in fire claims typically arise in several ways:

• Premature demolition or debris removal.If the fire scene is demolished or cleaned up before all interested parties have had an opportunity to investigate, critical evidence may be lost. This can happen when a municipality orders demolition for safety reasons, when a policyholder authorizes cleanup prematurely, or when the insurer itself arranges for demolition or debris removal before the policyholder's expert has had an opportunity to examine the scene.
• Failure to preserve physical evidence.When the insurer's C&O investigator removes items from the fire scene — a suspected electrical panel, an appliance, wiring — those items must be preserved. If the insurer or its investigator loses, destroys, or fails to maintain the chain of custody for physical evidence, that constitutes spoliation.
• Destructive testing without notice.If the insurer's expert intends to conduct destructive testing on evidence (testing that will alter or destroy the item), the policyholder and any other interested parties must be given notice and an opportunity to observe or participate. Destructive testing conducted unilaterally, without notice, is a recognized form of spoliation.

How C&O Findings Can Delay or Complicate Your Claim

The cause and origin investigation can have a significant impact on the timeline and outcome of your insurance claim. Here are the most common ways C&O findings create complications.

The “Pending Investigation” Delay

One of the most common effects of a C&O investigation is delay. The insurer will often take the position that it cannot finalize coverage or make payments while the investigation is pending. While an insurer has a right to investigate before making a final coverage determination, California law imposes strict timelines on the claims process. Under 10 CCR § 2695.7(b), the insurer must accept or deny a claim within 40 days of receiving proof of claim. Under 10 CCR § 2695.7(c), if the insurer needs additional time, it must provide written notice every 30 days explaining the reasons for the delay and the additional information needed. A C&O investigation does not give the insurer an unlimited license to delay.

Moreover, under 10 CCR § 2695.7(h), the insurer must continue to make interim payments for undisputed portions of the claim while investigating disputed issues. If the cause of the fire is in dispute but the existence and extent of the damage are not, the insurer should be making payments for the undisputed damage, additional living expenses, and contents losses while the C&O investigation continues. An insurer that withholds all payments pending completion of the C&O investigation may be violating the Fair Claims Settlement Practices Regulations.

Undetermined Cause Findings

Under NFPA 921, if the investigator cannot determine the cause of the fire to a reasonable degree of scientific certainty, the proper classification is “undetermined.” This is actually more common than many people realize — fire frequently destroys the very evidence needed to determine what caused it. An undetermined finding does not mean the fire was suspicious or that coverage should be denied. Under a standard homeowner's policy, fire is a covered peril, and the burden is on the insurer to prove an exclusion applies. An “undetermined” cause finding means the insurer has not identified a basis for denying the claim.

When the C&O Investigation Points to Arson

If the insurer's C&O investigator determines the fire was incendiary (intentionally set), the claim will almost certainly be referred to SIU for further investigation. If the insurer alleges the policyholder was involved in setting the fire, the claim will be denied. Under California law, the insurer bears the burden of proving arson by a preponderance of the evidence. The policyholder does not need to prove the fire was accidental — the insurer must prove it was intentional. If you are facing an arson allegation, get an attorney immediately. See our article on the innocent co-insured doctrine if the insurer alleges that someone else on the policy (a spouse, domestic partner, or co-owner) was involved.

When the Investigation Identifies a Subrogation Target

If the insurer's investigation identifies a third party as responsible for the fire, this creates a subrogation opportunity. This can be beneficial to you: if the insurer successfully pursues the responsible party, you may recover your deductible. However, the subrogation process can also complicate your claim in several ways.

• Your cooperation in the subrogation effort.Your policy requires you to cooperate with the insurer's subrogation efforts and to not do anything that would prejudice the insurer's right to recover from the responsible party. This means you should not release or settle with a potentially responsible third party without your insurer's knowledge and consent.
• Preservation of evidence for the subrogation case. If the insurer intends to pursue a product manufacturer or contractor, the physical evidence from the fire scene becomes even more critical. You may be asked to hold off on repairs, retain damaged components, or make the property available for additional inspections by the third party or their insurer.
• The “made whole” doctrine.Under California law, the policyholder has priority in any subrogation recovery. The insurer cannot recover through subrogation until the policyholder has been made whole for all losses, including those not covered by insurance. This is known as the “made whole” doctrine, and it protects you from a situation where the insurer recovers its money from the responsible party while you are still out of pocket for uncovered losses.

Challenging the Insurer's C&O Findings

If the insurance company's cause and origin investigation produces findings that are unfavorable to your claim — or findings you believe are inaccurate — you are not required to accept them. Here are the primary avenues for challenging insurer C&O conclusions:

• Retain your own fire investigation expert. As discussed above, you have the right to hire an independent fire investigator or forensic engineer to review the evidence and reach independent conclusions. Your expert should have qualifications that meet or exceed NFPA 1033 standards and should follow NFPA 921 methodology.
• Challenge the methodology.If the insurer's expert did not follow NFPA 921 — failed to consider alternative hypotheses, relied on outdated indicators, or reached conclusions unsupported by the physical evidence — the report is vulnerable to challenge. A well-qualified expert can identify methodological failures in the insurer's investigation.
• Challenge the qualifications.Not all fire investigators are created equal. If the insurer's C&O investigator lacks the education, training, or experience required by NFPA 1033, their opinions may be excludable as expert testimony under California's Kelly/Sargon framework. This is a question for your attorney, but it is worth raising.
• Obtain the fire department's report.If the fire department reached a different conclusion than the insurer's investigator — for example, the fire department classified the fire as accidental while the insurer's expert calls it incendiary — that discrepancy is significant evidence. The fire department's report is a public record and can be obtained through your local fire department.
• Request the insurer's complete file.Under California's Fair Claims regulations, you are entitled to know what information the insurer relied on. This includes the C&O report, photographs, laboratory results, and any communications between the insurer and the investigator. Review these materials carefully — or have your expert or attorney review them — for inconsistencies, unsupported conclusions, or evidence of bias. See our article on your right to claim documents.

Practical Steps for Policyholders During a C&O Investigation

1. Do not disturb the fire scene. Until all investigations are complete and all parties have released the scene, do not authorize demolition, debris removal, or significant cleanup. Take photographs and video of the scene as soon as it is safe to do so, before any evidence is moved.
2. Obtain the fire department report.Request a copy of the fire department's incident report as soon as it is available. This is a public record and you are entitled to it. It provides an independent baseline for the cause and origin determination.
3. Be present during the insurer's inspection.You have the right to be present (and to have your attorney, public adjuster, or own expert present) when the insurance company's C&O investigator examines the scene. Observe what the investigator looks at, what samples or items they collect, and what questions they ask. Take your own photographs during the inspection.
4. Be careful with statements.The C&O investigator may ask you questions about the fire, the property, appliances, recent repairs, electrical issues, and your whereabouts at the time of the fire. You have a duty to cooperate, but you also have the right to have counsel present. Be truthful, but be aware that your statements may be used in coverage determinations. See our guide on preparing for a recorded statement.
5. Document everything in writing.Every communication with the insurance company about the C&O investigation should be confirmed in writing. If the insurer tells you the investigation is delaying your claim, ask for the specific reasons in writing. If the insurer asks you to preserve specific evidence or refrain from certain actions, get the instructions in writing.
6. Preserve your own evidence.Keep all receipts, invoices, and records related to the property, including records of recent repairs, maintenance, appliance purchases, and electrical work. These records can be critical in establishing or refuting the investigator's conclusions about the fire's cause.
7. Know when to hire your own expert.If the insurer's C&O investigation is being used as a basis to deny your claim, delay payments, or limit coverage, consider retaining your own fire investigation expert. This is particularly important if the insurer's findings contradict the fire department's findings, if the cause is classified as “undetermined” but the insurer is treating the claim as suspicious, or if the insurer's report contains conclusions that do not align with the physical evidence as you understand it.
8. Consult an attorney if the claim is denied or if arson is alleged.If the insurer denies your claim based on C&O findings, or if there is any suggestion of arson or fraud, you need legal counsel immediately. Insurance Code § 2071’s standard-form 12-month suit-limitation provision has been statutorily extended to 24 months for residential property losses, and that clock is equitably tolled (paused) during the carrier’s active investigation and adjustment of the claim under Prudential-LMI Commercial Insurance v. Superior Court (1990) 51 Cal.3d 674 (see our equitable tolling guide). The endpoint of tolling is fact-specific — California courts have looked to when the carrier’s position becomes clear and final (a formal denial, an unequivocal repudiation, or the end of adjustment activity). In residential claims with long C&O investigations, the effective suit-limitation period can run considerably later than the face of the policy suggests. The specific timing is a question for counsel. Do not wait.

Regulatory Protections During C&O Investigations

California's regulatory framework provides significant protections for policyholders during the investigation process.

• Timely investigation.Under 10 CCR § 2695.7(b), the insurer must accept or deny the claim, in whole or in part, within 40 calendar days after receiving proof of claim. The investigation must be conducted promptly and diligently.
• Written status updates.Under 10 CCR § 2695.7(c)(1), if the insurer has not accepted or denied the claim within 40 days, it must provide written notice to the policyholder every 30 days explaining the reasons for the delay and stating the additional information needed.
• No unreasonable delay.Insurance Code § 790.03(h)(3) prohibits insurers from failing to adopt and implement reasonable standards for the prompt investigation and processing of claims. An investigation that drags on without justification may violate this provision.
• Interim payments.Under 10 CCR § 2695.7(h), the insurer must not delay payment of undisputed amounts while investigating disputed issues. If the existence and amount of your additional living expenses are not in dispute, those payments should continue regardless of the status of the C&O investigation.
• Good faith duty to investigate.The insurer's duty of good faith and fair dealing extends to the investigation itself. An investigation that is conducted with the purpose of finding a reason to deny the claim — rather than to fairly determine the facts — may constitute bad faith. As the California Supreme Court stated in Egan v. Mutual of Omaha Insurance Co. (1979) 24 Cal.3d 809, the implied covenant of good faith and fair dealing requires the insurer to give at least as much consideration to the insured's interest as it gives to its own.

Filing a Complaint with the Department of Insurance

If you believe the insurer is using the C&O investigation to unreasonably delay your claim, withhold payments, or engage in other unfair practices, you have the right to file a complaint with the California Department of Insurance (CDI). The CDI has regulatory authority to investigate insurer conduct and enforce the Fair Claims Settlement Practices Regulations. For guidance on this process, see our article on filing a CDI complaint.

The Bottom Line

A cause and origin investigation after a fire is standard practice. What is not standard — or acceptable — is an insurer that uses the investigation as a tool to delay payments, pressure policyholders, or manufacture reasons to deny otherwise valid claims. The fire department investigates whether a crime was committed. The insurance company investigates whether someone else can be made to pay. These are fundamentally different inquiries conducted by parties with fundamentally different interests, and policyholders should understand that distinction from the very beginning.

Know your rights, preserve the evidence, document everything, and do not hesitate to bring in your own experts or legal counsel if the investigation is being used against you. California law provides substantial protections for policyholders — but those protections only work if you invoke them.

Related Resources

• Subrogation in Property Insurance
• Fire Damage Insurance Claim Denied? Here's What to Do
• When Your Claim Is Referred to SIU
• Challenging Insurance Company Engineering Reports
• Smoke Damage Insurance Claims
• Duties After Loss
• Preparing for a Recorded Statement
• The Innocent Co-Insured Doctrine
• California Fair Claims Settlement Practices
• Fire Damage Insurance Claim Denied? Here's What to Do
• How the Standard Fire Policy Turns Denials Into Coverage

Written by Leland Coontz III, Licensed Public Adjuster, CA License #2B53445.