Video footage shows a father frantically chasing a train after he stepped off to have a cigarette and it left the station with his baby on board.
The clip shows the man putting the child’s carrier down on a seat inside a carriage before getting off the train.
A short while later a fellow passenger bangs on the window and gestures to the father to get back on the train but the doors close as he runs towards it.
The parent can be seen running after the train while another man calls for help on his phone and stays by the baby’s side.
The train's driver is said to have been alerted to the situation and quickly returned to the station where the pair were reunited.
The surveillance footage was released by Greater Cleveland Regional Transit Authority following the incident in East Cleveland, Ohio, on 12 January.
The authority said the driver learned about the baby on board before arriving at the next station, which was only a minute away, and quickly returned.
