Amtrak train 94 , the `` Colonial '' , ( now part of the `` Northeast Regional '' ) traveling north from Washington , D.C. , to Boston , crashed Motion into a set of Conrail locomotives running light ( without freight cars ) , and which had fouled Motion ( entered ) the mainline .

The Conrail locomotive crew failed to stop Motion at the signals before Gunpowder Interlocking , and it was determined Deciding that the accident would have been avoided Preventing_or_letting had they done so .