April 10, 1963: The American nuclear attack submarine U.S.S. Thresher fails to resurface after a test dive 350 km east of Boston, killing 129. The probable cause: a leak in an engine room seawater piping system. Sept. 8, 1967: Fire breaks out in the hydraulic system of a Soviet November-class sub in the Norwegian Sea. The submarine manages to resurface, but 39 crewmen die.
May 24, 1968: A reactor fault on a Soviet sub designated K-27 releases radiation that heavily contaminates the interior. The submarine is scuttled in the Kara Sea in 1981.
May 22, 1968: The U.S.S. Scorpion sinks 640 km southwest of the Azores after a suspected torpedo malfunction. All 99 aboard are killed.
April 8, 1970: Fires break out in a submerged Soviet November-class boat in the Bay of Biscay. It surfaces, but the fires rage out of control for three days until the vessel sinks with a loss of 52 lives.
Feb. 24, 1972: A rupture in a hydraulic fluid line starts a fire in a Soviet Hotel-class sub in the North Atlantic. Crewmen fight the fire for 24 days before being rescued, but 28 die.
Aug. 21, 1980: Fire and radioactive leakage force a Soviet Echo-I-class sub to surface off the coast of Japan. Nine die.
Oct. 6, 1986: A Soviet Yankee-class ballistic missile submarine sinks off Bermuda after an explosion in a missile tube. Four crewmen die.
April 7, 1989: Fire breaks out in the Soviet attack submarine Komsomolets in the Norwegian Sea, where it sinks with the loss of 42 lives.
Aug. 12, 2000: The Russian attack submarine Kursk sinks in the Barents Sea after an explosion in the forward area. Rescue attempts fail, and all 118 on board die.