In 1975, prisoners at a jail in Saltillo, Mexico, began to dig a tunnel that would take them beyond the prison walls to freedom. They labored long and hard on the project, and in April 1976, it was completed.
When the would-be escapees came up out of the tunnel, however, they found themselves in the very courtroom in which most of them had been sentenced to prison! All the convicts were promptly returned to their cells.
The guards at another Mexican prison, at Alamos, might have been more alert than their counterparts at Saltillo. A regulation at the Alamos prison once demanded that a guard serve out the sentence of any convict who managed to escape while the guard was on duty.