And for one man, it was a life-changing save.
Video from the BART station at the Coliseum in Oakland, California shows the moment a man stumbled and fell just as a train was coming.
An alert transit worker reached down and pulled him up just in time.
The two men, both shaken up, but unhurt, shared an emotional hug right afterward.
The oncoming train was just about 60-feet away when the incident occurred.