1933 United Airlines Boeing 247 mid-air explosion

On October 10, 1933, a Boeing 247 airliner operated by United Airlines and registered as NC13304 crashed near Chesterton, Indiana. The transcontinental flight carried three crew and four passengers and originated in Newark, New Jersey, with its final destination in Oakland, California. It had already landed in Cleveland and was headed to its next stop in Chicago when it exploded en route. All aboard died in the crash, which was caused by an on-board explosive device. Eyewitnesses on the ground reported hearing an explosion shortly after 9 p.m. and seeing the aircraft in flames at an altitude of about 1,000 feet . A second explosion followed after the aircraft crashed. The crash scene was adjacent to a gravel road about 5 miles outside of Chesterton, centered in a wooded area on the Jackson Township farm of James Smiley.
Investigators combed through the debris and were confronted with unusual evidence: the toilet and baggage compartment had been smashed into fragments. Shards of metal riddled the inside of the toilet door, while the other side of the door was free of the metal fragments. The tail section had been severed just aft of the toilet and was found mostly intact almost a mile away from the main wreckage. On November 16, 2017, the Federal Bureau of Investigation declassified 324 documents related to the investigation.

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