The battery of a Tesla Model S reignited twice after it was involved in a crash that killed an 18-year-old driver and passenger in Fort Lauderdale, Florida, last month, a federal investigation has revealed.
The driver was speeding, clocking 116 mph in a 30 mph zone, when he lost control of the vehicle while trying to pass in a curve, according to the US National Transportation Safety Board’s preliminary report released Tuesday.
The car jumped the curb and hit a wall twice before erupting in flames. The driver and front-seat passenger died at the scene and the surviving back-seat passenger was ejected from the vehicle.
Emergency responders used almost 300 gallons of water and foam to extinguish the fire and pieces of the battery that broke off from the main part, said the report. However, it continued, “During the loading of the car for removal from the scene, the battery reignited and was quickly extinguished. Upon arrival at the storage yard, the battery reignited again.”
Tesla declined to comment on this story.
Tesla uses a 400-volt lithium-ion high-voltage battery in its 2014 Model S cars. Lithium-ion batteries comprise flammable materials; the Samsung Note 7 phone explosions were partly tied to overheating lithium-ion batteries.
“Battery fires can take up to 24 hours to fully extinguish,” according to Tesla’s Emergency Response Guide for the 2014 Model S. “A damaged high-voltage battery can cause rapid heating of the battery cells. If you notice smoke coming from the battery area, assume the battery is heating and take appropriate action.”
In the guide, Tesla wrote that firefighters should use a thermal imaging camera to make sure the battery is completely cooled. “If a thermal imaging camera is not available, you must monitor the battery for re-ignition,” the company directed.
In manuals for more recent Tesla models—which contain the same type of battery—the company’s Emergency Response Guides recommend using 3,000 gallons of water to fully extinguish a battery fire.
In mid-2016, Tesla tapped Jeff Dahn, a world-leading battery researcher from Canada’s Dalhousie University, to help develop better, safer lithium-ion batteries using alternative components. The five-year exclusive partnership was reportedly struck to “develop lithium-ion batteries for automobiles and grid energy storage that are cheaper, more powerful and longer lasting, thus helping to ensure the wider adoption of electric vehicles and renewable energy.” Dahn declined Motherboard’s interview request, citing proprietary reasons.
Other Teslas have caught on fire. Earlier this month the battery of the car belonging to the husband of West Wing actor Mary McCormack caught fire while sitting in traffic in Los Angeles. No one was injured in that incident, and Tesla told CNN it was “extraordinarily unusual.”
Update: This story has been updated to note Tesla declined to comment.