Investigators from the National Transportation Safety Board are meeting with Amtrak engineer Brandon Bostian on Friday, according to NBC News.

It’s unclear where the meeting will be held, but a press conference has been scheduled for Friday afternoon.

Investigators are trying to figure out why Bostian’s train suddenly revved up to 106 mph just before it took a sharp turn and ran off the rails, killing eight people and injuring over 200 in the crash.

Investigators obtained a warrant for Bostian’s cell phone records and will be checking to see if he was using it at the time, The Philadelphia Inquirer reported.