ROSEDALE, Md. (AP) — Federal investigators say a CSX freight train was traveling 49 mph and that the engineer blew a whistle three times before it collided with a garbage truck outside Baltimore, leading to a derailment, explosion and chemical fire.

Robert Sumwalt of the National Transportation Safety Board said Wednesday that the train hit the right rear axle of the truck as it was crossing the tracks around 2 p.m. Tuesday.