Cave In

Shut up! have done! Iʹll cave in his head (break it). His fortune has caved in (has failed). The bank has caved in (come to a smash). The affair caved in (fell through). Common American expressions.

In the lead diggings, after a shaft has been sunk, the earth round the sides falls or caves in, unless properly boarded; and if the mine does not answer, no care is taken to prevent a caving in.