American aquanaut Berry L. Cannon dies of carbon dioxide poisoning while attempting to repair a leak in the SEALAB III underwater habitat. The SEALAB project was subsequently abandoned.

Berry Louis Cannon was an American aquanaut who served on the SEALAB II and III projects of the United States Navy. Cannon died while attempting to repair SEALAB III. A U.S. Navy Board of Inquiry concluded that Cannon died of carbon dioxide poisoning, and that his diving rig's baralyme canister, which should have absorbed the carbon dioxide Cannon exhaled, was empty.

SEALAB I, II, and III were experimental underwater habitats developed and deployed by the United States Navy during the 1960s to prove the viability of saturation diving and humans living in isolation for extended periods of time. The knowledge gained from the SEALAB expeditions helped advance the science of deep sea diving and rescue and contributed to the understanding of the psychological and physiological strains humans can endure.

February 17 is the 48th day of the year in the Gregorian calendar; 317 days remain until the end of the year.