Lyric discussion by MyClockIsOrange 

Cover art for Stop That Train lyrics by Bob Marley and the Wailers

Achingly sad song (about someone contemplating suicide), beautifully written & sung by Peter Tosh. The best version can be found on the Live at Capitol Studios boot from 1973 (also know as Live at the Record Plant).

The Wailers weren't all sunshine/good vibes at this time, as witnessed by songs like Concrete Jungle, Bob's grim opener on the Catch a Fire album.