The National Transportation Safety Board said a Tesla Model S P100D crashed shortly after 9 p.m. April 17 along a residential road in Spring, Tex., killing the owner and a passenger.

In an update Thursday, safety investigators described the sequence of events they believe led to the crash. They said the trip started at the owner’s home near a cul-de-sac when the 59-year-old owner climbed into the driver’s seat and a 69-year-old sat in the passenger seat.

“The car leaves and travels about 550 feet prior to departing the road on a curve, driving over the curb, and hitting a drainage culvert, a raised manhole, and a tree,” the safety board wrote in the update.

The driver had pressed hard on the accelerator, data showed, as “application of the accelerator pedal was found to be as high as 98.8 percent." In the five seconds before the crash, the NTSB said, the car sped up to 67 mph.

“The crash damaged the front of the car’s high-voltage lithium-ion battery case, where a fire started," authorities said.

Tesla did not immediately respond to a request for comment.

The NTSB said the car’s event data recorder, which was damaged in the fire but repaired by investigators with the help of the module’s manufacturer, showed occupants in both front seats with their seat belts buckled at the time of the crash. The NTSB also said a post-crash inspection showed the steering wheel was deformed “due to an impact.”