Feb. 12, 2020—Federal investigators released documents on two Tesla crashes involving Autopilot, according to a report by USA Today.

The National Transportation Safety Board (NTSB) is investigating the March 23, 2018 crash that killed Walter Huang near Mountain View, Calif. It’s also probing a crash in Delray Beach, Fla., that happened about a year later and killed driver Jeremy Banner.

The full NTSB board is scheduled to hold a hearing on the Mountain View crash on Feb. 25., and determine a cause. 

In addition to documents released, records from an iPhone recovered from the crash site showed that Huang may have been using it before the accident. Records obtained from AT&T showed that data had been used while the vehicle was in motion, but the source of the transmissions couldn’t be determined, the NTSB wrote. One transmission was less than a minute before the crash.

In the Florida crash, Banner turned on the Autopilot function of his Model 3 sedan 10 seconds before the crash, then took his hands off the steering wheel, NTSB documents said. The car then drove underneath a tractor-trailer that was crossing in front of it, sheering off the car’s roof and killing Banner, according to USA Today.