Three cars stop in the same lane after a collision. The middle driver says the last car pushed them into the first. The last driver says the front two had already collided. Both explanations can produce similar final positions, but they describe different actions and potentially different responsibility for the injuries.
Reconstructing a chain reaction means establishing each contact separately. Start with what each vehicle was doing before the first impact, then compare the accounts with damage, recordings, scene measurements, and any usable vehicle data.
Give each impact its own place on the timeline
An occupant may remember one hard jolt followed by a lighter one. Another may remember a pause or hear a crash before feeling contact. Record those details in the person’s own words, including uncertainty. Surprise, noise, pain, and closely spaced impacts can make precise timing difficult.
Ask whether the middle vehicle had stopped behind the first, whether it was already touching the first vehicle, and whether anyone saw its brake lights or movement. Identify witnesses by what they could actually see. Someone who looked up after a bang may describe the aftermath accurately without having seen what started it.
Photograph every side of every vehicle, with wide views connecting the cars to the lanes, intersection, debris, and marks on the road. Note when a vehicle was moved for safety or traffic control. Its position in a later photograph may differ from its resting position immediately after the collision.
Compare evidence that answers different questions
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| Evidence | What to compare | Limit to account for |
|---|---|---|
| Damage photographs and inspections | Contact heights, transferred material, and front and rear damage on the middle car. | A repair estimate lists damage; it does not establish when each contact occurred. |
| Scene measurements | Debris, tire marks, road slope, and the vehicles’ documented positions. | Traffic, responders, weather, or towing may change the scene. |
| Original recordings | The approach, first contact, any pause, and later movement. | A blocked view or low frame rate may conceal a separate impact. |
| Witness accounts | Each person’s viewing position and the movement they observed. | Hearing two sounds is different from seeing two contacts. |
| Vehicle event data | Available inputs and crash measurements alongside the physical evidence. | One stored event may not describe every impact in the sequence. |
Keep enough footage to see the approach
A clip beginning with the largest impact may leave out an earlier collision. Preserve original dashcam, business, residential, or traffic recordings with enough time before and after the crash to understand the sequence. Keep the original file and identify its camera, location, and clock setting.
When two recordings show different times, compare an event visible in both before aligning them. An apparent gap between impacts may reflect different clocks. Our guides to evidence in a Louisiana car accident claim and collecting car accident documentation explain how recordings fit with the other records.
Preserve vehicles before evidence disappears
NHTSA describes event data recorders as devices that can retain brief crash-related information, such as vehicle dynamics, driver inputs, and restraint-system information. These are not continuous video or audio recordings. Available information depends on the vehicle, equipment, and event.
Before a vehicle is repaired or sent to salvage, consider whether a qualified inspection or data retrieval is needed and arrange lawful access. Compare any downloaded record with the damage and recordings. A reconstruction should explain the evidence supporting its sequence and the alternatives that cannot be excluded.
Connect fault to the conduct that caused the loss
Rear damage alone cannot resolve whether a middle driver first struck another car or was pushed into it. Louisiana Civil Code article 2323 requires allocating fault among people who caused or contributed to the loss. For ordinary negligence claims governed by its current version, a claimant’s negligence of 51 percent or more bars recovery; below that threshold, damages are reduced proportionately. The amendment took effect January 1, 2026, so the crash date matters.
A useful case timeline identifies each proposed contact, its supporting evidence, and any unresolved conflict. The Baton Rouge car accident practice explains how that investigation connects with insurance and injury documentation.
Editorial & Legal Accuracy Notice (Louisiana)
Sources checked: September 30, 2026.
This article provides general information. Responsibility depends on the crash sequence, available evidence, and the law governing the event.