Saved by the bell

 
Saved by the bell means saved by a last minute intervention.

It is said to originate in boxing and is first noted in the latter half of the 19th century. A boxer in danger of defeat can be 'saved' by the bell marking the end of a round.

There is a common misconception that the phrase is from the 17th century and describes people being saved after being buried alive thanks to being buried in a coffin from which ran a cord with a bell attached. Such coffins did exist and the person who had died - or his relatives - would arrange for someone to be paid to sit overnight in the graveyard to listen out for the bell. This became known as the graveyard shift.