REDISCOVERY OF THE 1945 ESCAPE TUNNEL AT EASTERN STATE PENITENTIARY HISTORIC SITE, PHILADELPHIA

On April 3, 1945 twelve prisoners escaped from Eastern State Penitentiary through a tunnel that began in a cell at the end of Cell Block 67 and exited outside the penitentiary wall near the corner of 22nd St and Fairmount Avenue. In anticipation of the 60th anniversary of the escape, John Milner Associates, Inc. (JMA) was contracted to relocate the exit of the tunnel using standard excavation techniques and the entrance using a jackhammer. Ground-penetrating radar (GPR) was used to determine the alignment of the tunnel across the penitentiary yard. Guided by the interpreted GPR anomalies, JMA used a hand auger at two locations to relocate the tunnel. The first location was determined collapsed while the second location revealed the interpreted tunnel at approximately 8.5 ft below grade. Initially, a sewer camera was used to confirm that the void was indeed related to the escape tunnel. After confirmation, a remote controlled Crawler camera was lowered into the hole and moved on caterpillar treads up the narrow tunnel, filming its progress as it went. Live images of the escape tunnel were broadcast to the surface, were recorded, and were projected live onto a screen for the public to view during a public event. The detailed footage further confirmed that the void was in fact the 1945 escape tunnel.