USS Thresher

Two submarines of the United States Navy have been named USS Thresher, for a type of shark that is harmless to man and easily recognizable because its tail is longer than the combined length of body and head.

The first USS Thresher (SS-200), was a Tambor-class submarine[?] that served in World War II.

The second USS Thresher (SSN-593), was the lead ship of her class[?] of nuclear-powered attack submarines and was lost by accident on April 10th, 1963 during depth trials, taking the lives of 129 men.

It is believed that failure in a crucial weld caused water to leak into an engineering compartment, which caused electrical systems aboard to fail. Without electrical power, the nuclear reactor shut down as designed, leaving the sub without its main source of propulsive power. The sub was unable to surface by available emergency means.