After Tesla and the U.S. National Transportation Safety Board (NTSB) had a fallout over the board’s investigation into a deadly crash involving a Tesla vehicle on Autopilot, the NTSB is launching yet another investigation into an accident involving a Tesla vehicle.

This time, they are mainly focused on “the emergency response in relation to the electric vehicle battery fire” as we find out that batteries from the other crash under investigation reignited days after the accident.

The new crash under investigation involves three teens who crashed into a concrete wall in a Tesla Model S earlier this week.

Two of them died as a result of the accident and one was at the hospital in an unknown condition as of yesterday.

The NTSB issued a statement announcing their investigation into the crash. NTSB Chairman Robert S. Sumwalt commented:

“NTSB has a long history of investigating emerging transportation technologies, such as lithium ion battery fires in commercial aviation, as well as a fire involving the lithium ion battery in a Chevrolet Volt in collaboration with the National Highway Traffic Safety Administration.  In addition, the NTSB is currently investigating a fire involving the transportation of hydrogen gas for fuel cell vehicles. The goal of these investigations is to understand the impact of these emerging transportation technologies when they are part of a transportation accident.”

They sent 4 investigators to Florida and they will “primarily focus on emergency response in relation to the electric vehicle battery fire, including fire department activities and towing operations.”

It comes just as we learned that the Mountain View Fire Department shared a report with other fire departments about the aftermath of the fatal Tesla Model X accident in Mountain View that is now also under NTSB investigation.

In the report (via KTVU), the fire department said that they monitored the battery pack and it reignited days after the March 23 accident.

Mountain View Fire Chief Juan Diaz commented:

“In this particular case, six days later, the temperature inside those cells increased to the point of ignition. That’s why the car reignited. You have stored energy that is frankly unstable.”

Tesla recommends using “large amounts of water” to extinguish a battery fire in its vehicles and to use a thermal imaging camera to monitor the battery for at least one hour after it is found to be completely cooled:

“If the high voltage battery catches fire, is exposed to high heat, or is bent, twisted, cracked, or breached in any way, use large amounts of water to cool the battery. DO NOT extinguish with a small amount of water. Always establish or request an additional water supply.”

The company also offers online training for fire departments about how to handle its vehicles after a crash.

In the case of the March 23 accident, Tesla was able to send engineers to assist the firefighters in removing the vehicle and its battery pack from the scene since it was near its factory and headquarters (pictures via Dean C. Smith on Twitter):

Electrek’s Take

As usual, it’s important to remind everyone that even though electric vehicle fires are heavily represented in the media, EVs don’t catch on fire more often than gasoline cars. According to the National Fire Protection Association, more than 150,000 gasoline car fires occur in the U.S. every year.

But with this said, battery fires do burn differently and therefore, it is important for first responders to know how to handle them.

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