Saved By the Bells

 There's a grim origin for the saying "saved by the bell". When ancient European people realised people were being buried before they had fully expired, they decided to tie a string to the "dead" person's hand, and tied the other end of the string to a bell and tied that to a tree branch. If the person revived enough to ring the bell, there would be a rush to dig them up. So a few were probably saved by the bell.