June 11, 1962 (based on true story)
Frank Morris, John Anglin, Clarence Anglin may have successfully carried out one of the most intricate escapes ever devised on June 11, 1962. Behind the prisoners' cells in Cell Block B (where the escapees were interned) was an unguarded 3-foot (0.91 m) wide utility corridor. The prisoners chiseled away the moisture-damaged concrete from around an air vent leading to this corridor, using tools such as a metal spoon soldered with silver from a dime and an electric drill improvised from a stolen vacuum cleaner motor. The noise was disguised by accordions played during music hour, and their progress was concealed by false walls which, in the dark recesses of the cells, fooled the guards.
The escape route then led up through a fan vent; the fan and motor had been removed and replaced with a steel grille, leaving a shaft large enough for a man to climb through. Stealing a carborundum cord from the prison workshop, the prisoners had removed the rivets from the grille and substituted dummy rivets made of soap. The escapees also stole several raincoats to use as a raft for the trip to the mainland. Leaving papier-mâché dummies in their cells, they escaped. The prisoners are estimated to have entered San Francisco Bay at 9:30 p.m.
The official investigation by the FBI was aided by another prisoner, Allen West, who also was part of the escapees' group but was left behind. West's false wall kept slipping, so he held it in place with cement, which set. When the Anglin brothers (John & Clarence) accelerated the schedule, West desperately chipped away at the wall; but by the time he did his companions were gone. Articles belonging to the prisoners (including plywood paddles and parts of the raincoat raft) were found floating in the bay and the official report on the escape says the prisoners drowned while trying to reach the mainland in the cold waters of the bay. but there were sightings of the three men over the Years, and Friends and family of the Anglins claimed to have been having postcards written in the Brothers handwriting.
Certain aspects of the escape proved it might have been successful as it was recreated on hit discovery TV show Mythbusters