There were 23 collisions, 7 battery gas explosions, 12 gasoline explosions, and 13 sinkings due to hull openings not being closed. HMS Affray was lost in the English Channel in 1951 due to the snort mast fracturing and USS Thresher in 1963 due to a pipe weld failure during a test dive. Many other scenarios have been proven to be probable causes of sinking, most notably a battery malfunction causing a torpedo to detonate internally, and the loss of the Russian Kursk on 12 August 2000 probably due to a torpedo explosion.