Tesla crash that killed two Florida teens probed by NTSB investigators

Marco della Cava | USA TODAY

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SAN FRANCISCO — The National Transportation Safety Board said Wednesday that it was sending four investigators to probe a Tesla Model S crash that killed two Florida teens when it hit a concrete wall and burst into flames.

Two Fort Lauderdale high school students were killed in the crash Tuesday night, while a third 18-year-old was ejected from the vehicle and taken to a local hospital, according to Miami's NBC 6.

The car's speed — and not the electric automaker's partial self-driving Autopilot system — is considered the main culprit in the accident, according to both the NTSB and Tesla. The 2014 Model S was in a residential zone with a 35-mph limit.

Instead, the decision to a launch an investigation centers on the fire that erupted after the battery-powered sedan hit the wall.

“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,” NTSB Chairman Robert Sumwalt said in a statement.

"The goal of these investigations is to understand the impact of these emerging transportation technologies when they are part of a transportation accident," he said.

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Tesla, based south of San Francisco in Palo Alto, Calif., did not respond to an immediate request for comment, but issued a statement to NBC 6 saying that it had so far not been able to retrieve a vehicle identification number which would allow the company to access the car's computer logs.

"However, had Autopilot been engaged it would have limited the vehicle’s speed to 35 mph or less on this street, which is inconsistent with eyewitness statements and the damage to the vehicle," Tesla's statement said.

This is the second time in recent months that a Tesla accident has drawn the attention of the NTSB, which is still investigating a March Model X crash in Mountain View, Calif., that killed its driver. That vehicle was in Autopilot mode when it hit a concrete barrier.

Tesla said the driver ignored repeated warnings from the car to take back control. But in reporting details of the crash on its website, it raised the ire of the NTSB, which said the release of such information was premature. The NTSB subsequently removed Tesla as a party in its investigation; Tesla said it chose to withdraw to defend its position.

That fatal Model X crash also sparked a fire that took hours to put out, according to reports.

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Experts say that once ignited, lithium-ion batteries — the same kind found in laptops and cellphones, though in far smaller quantities than cars — have a tendency to ignite in a chain reaction and burn considerably hotter than the lead-acid batteries in conventional gasoline-powered vehicles.

The latest NTSB investigation into a Tesla crash is likely to cause more grief for a company trying to ramp up production of its mission-critical Model 3 entry-level electric sedan. But some industry observers wonder whether the spotlight is warranted.

"Based on annual statistics, about 500 gas-powered cars catch on fire, and around 100 people die on U.S. roads every day," Fred Lambert, founder of electric vehicle site Electrek, wrote Wednesday. "Those stories generally never go past local news outlets, but when a Tesla vehicle is involved, it suddenly makes national news."

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