The question of whether Bostian should be prosecuted has long taken an unusual path. The engineer had been conducting Amtrak Northeast Regional Train No. 188 on May 12, 2015, as it carried more than 250 passengers and hit the Frankford Curve in Port Richmond while traveling 106 m.p.h. — more than double the speed limit. Eight people died in the derailment and more than 150 were injured.