​On February 9, 2001, approximately nine nautical miles south of Oahu, Hawaii, the USS Greeneville (SSN-772) was involved in a collision with Ehime Maru, a Japanese fishing trawler and high-school training ship. To demonstrate her capabilities for onboard VIPs, the Los Angeles-class nuclear attack submarine performed an emergency blow, during which she struck the Japanese ship, which sank minutes later.

We ​​determined that the probable cause of the collision of the USS Greeneville with the Japanese fisheries training vessel Ehime Maru was the inadequate interaction and communication among senior members of the combat systems team (the commanding officer, the officer of the deck, the fire control technician, and the sonar supervisor), which resulted in the failure to perform adequate contact analysis and adhere to proper procedures for moving to periscope depth; and the commanding officers decision to order an emergency surfacing maneuver. 

Contributing to the cause of the accident was the failure of the crew, in particular the commanding officer, to adequately manage the civilian visitors so that they did not impede operations.

Contributing to the loss of life was the rapid flooding and sinking of the Ehime Maru, which occurred when the submarines rudder tore through the fishing vessel s lower deck spaces.