The Byford Dolphin Diving bell accident

From Wikipedia:

At 4:00 AM on November 5, 1983, four divers were in a Decompression chamber system attached to a diving bell on the rig, being assisted by two dive tenders. One diver was about to close the door between the chamber system and the trunk when the chamber was explosively decompressed from a pressure of 9 atm to 1 atm in a fraction of a second. Five of the men were killed; the other was severely injured.

Diver D4 was shot out through the small jammed hatch door opening, and was ripped apart. Subsequent investigation by forensic pathologists determined that diver D4, being exposed to the highest pressure gradient, violently exploded due to the rapid and massive expansion of internal gases. All of his thoracic and abdominal organs, and even his thoracic spine were ejected, as were all of his limbs. Simultaneously, his remains were expelled with force through the narrow trunk opening left by the jammed chamber door, less than 60 centimeters (24 inches) in diameter. Fragments of his body were found scattered about the rig. One part was even found lying on the rig’s derrick, 10 meters (30 feet) directly above the chambers. His death most likely was instantaneous and painless.