720 Naval Reactors History Database (f1-date=1963) Results for your query: f1-date=1963 Tue, 01 Jan 1963 12:00:00 GMT Brass pipe recovered from wreckage of USS Thresher. Photograph of a brass pipe recovered from the wreckage of the USS Thresher in 1963. The pipe was recovered by the bathyscaph Trieste, and it has the information "593 Boat" etched on the pipe. The Thresher was lost on 10 April 1963, with the loss of 129 crewmen and civilian workers. A court of inquiry determined that the most probable cause of the Thresher's loss was a seawater leak that led to a loss of electrical and propulsion power. Tue, 01 Jan 1963 12:00:00 GMT