A Tesla Inc. electric car that “no one” appeared to be driving crashed late Saturday in Texas, erupting into flames and killing the two passengers, according to local authorities.

One victim was found in the front passenger seat of a 2019 Model S and the other was in the rear, Harris County Precinct 4 Constable Mark Herman said in a telephone interview. The car ran into a tree north of Houston after traveling at high speed and failing to navigate a turn.

The position of the victims, statements and other physical evidence suggest that “no one was driving the vehicle at the time of impact,” Herman said. “It’s still under investigation.”

Herman said his office is coordinating with federal authorities, without specifying which ones, and didn’t know whether the Autopilot feature was engaged. It took more than 30,000 gallons (113,562 liters) of water to extinguish the fire, which burned for four hours, he added.

Tesla didn’t immediately respond to a request for comment Sunday. The company’s shares fell as much as 2 per cent in U.S. pre-market trading on Monday.

Federal officials have criticized Tesla for fire risks related to the battery packs in its cars and for not doing enough to keep drivers from using its driver-assist function inappropriately. In a hearing last year, the National Transportation Safety Board’s chairman said that “it’s time to stop enabling drivers in any partially automated vehicle to pretend that they have driverless cars.”

NTSB, which has investigated numerous previous Tesla crashes, isn’t planning on opening a new probe into the latest incident, spokesman Chris O’Neil said.

Tesla Chief Executive Officer Elon Musk has defended the safety record of his company’s vehicles. This week, he shared a report on Twitter, saying that a Tesla with Autopilot engaged is now approaching a “10 times lower” chance of an accident than an average vehicle.