The family suffered severe injuries and said Tesla's airbags should have deployed. Cohen Milstein

A Tesla Model 3's airbags didn't inflate in a devastating highway accident earlier this year, the victims' attorney said.

The family's lawyer said he sent a routine "preservation letter" to the company but hasn't heard back in the month since.

"Tesla has the ability to monitor their vehicles out on the roadway. Who owns that data? Is it our client? Is it Tesla?" the attorney said.

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When a Tesla Model 3 carrying Kristian Henderson and her family slammed into a guardrail on the Interstate 95 median in suburban Maryland this summer, the vehicle's side airbags didn't deploy, according to the victims' attorney.

The George Washington University professor was rendered comatose by the impact, causing her serious brain damage, while her son in the back seat also suffered severe injuries, their lawyer, Ted Leopold of Cohen Milstein, said.

Many of those injuries could have been prevented if the airbag had functioned as designed, Leopold said, alleging that Tesla hasn't made the investigation any easier. The attorney sent a routine preservation letter to Tesla in August, but he said the company has yet to get back to him. The family is considering filing a lawsuit if the electric-car maker doesn't respond, he said.

Cohen Milstein

"This case will be, to my knowledge, the first case like this against Tesla," Leopold said in an interview. "They certainly have promoted their expertise in the IT area, and I'll be curious from a safety perspective how strong they are and how their development in that area has been."

"These are routine cases for Ford, General Motors, and others," he said.

A Tesla representative said the company did, in fact, respond and was waiting for more information from the victim's lawyer.

Leopold also pointed to documents revealed last month by PlainSite that showed that the National Highway Transportation Safety Administration had warned Tesla to tone down its language with regard to safety. The agency sent a cease-and-desist letter in October after CEO Elon Musk said there was "no safer car in the world" than a Tesla, according to the documents.

"The fact that they self-promote that it's safe when the government told them they can't do that, first-blush indication is that on this vehicle, the safety mechanisms failed," Leopold said.

A Tesla representative declined to comment on the record for this story but said airbags weren't necessarily designed to fire in all circumstances, depending on the crash, according to NHTSA. The representative also pointed to Tesla's five-star crash rating and a blog post saying that the company's vehicles were "engineered to be the safest cars in the world."

Leopold said that marketing effort was exactly why getting ahold of the crash data should be easy.

"Tesla has the ability to monitor their vehicles out on the roadway. Unlike Ford or General Motors or Toyota, Tesla seems to have that ability. Who owns that data? Is it our client? Is it Tesla? Certainly we're going to seek it, and they should voluntarily provide it to us," he said.

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