What happened
During a routine Cold War era training flight originating from Loring AFB, Maine, a B-52 bomber experienced a catastrophic structural failure while flying at night. While cruising at an altitude of 36,400 feet over the state of Minnesota, the aircraft's tail section separated from the fuselage, sending the plane into a high-speed descent.
The aircraft plummeted from its cruising altitude to approximately 8,000 feet in just 108 seconds. The flight ended in a massive explosion in Inver Grove Heights, located roughly 7.5 miles south of Saint Paul. The impact and subsequent fire resulted in the total destruction of the airframe. Of the eight crew members on board, seven fatalities were recorded, while one member of the crew survived the accident.
Findings
Investigations into the crash suggested that a failure of the control cables during flight led to the aircraft entering an extreme attitude. This loss of control was believed to have created enough aerodynamic stress to shear the tail section away from the rest of the bomber. While the mechanical failure of the cables was identified as the primary driver of the accident, the specific origin of the technical malfunction remained undetermined.