The U.S. Navy has fired the commanding officer of the nuclear-powered submarine that crashed into an underwater mountain last month. Commander Cameron Aljilani, the executive officer and highest-ranking official onboard the vessel, was relieved of his position after investigators concluded that the incident could have been prevented.

Two other sailors were also removed from their positions by the U.S. Navy on Thursday. The decision came after the investigation into the matter had concluded. Aljilani will be replaced by another officer who will act as the vessel's interim commander.

The USS Connecticut is a Sea Wolf-class attack submarine with a full complement of 140 crewmembers. The vessel was under the command of 14 naval officers when it crashed.  The submarine is heavily armed with eight torpedo tubes, and it features the Navy's most advanced sensors.

Aljilani was in charge of the USS Connecticut when it was on routine patrol in the disputed South China Sea. The submarine reportedly crashed into an uncharted rock formation, known as a "seamount," while it was underwater. The crash damaged the submarine and forced it to surface for close to a week.

It then traveled while surfaced to Guam. The submarine is currently undergoing damage assessment before it will be sent to the U.S. submarine base in Bremerton, Washington, for repairs.  

 The western Pacific-based 7th Fleet concluded that a lack of "sound judgment" and prudent decision-making had led to the crash. It added that the proper team execution and risk management would have prevented the crash.

Around 11 sailors were injured during the crash, which damaged the vessel's forward ballast tanks. Fortunately, the submarine's nuclear power plant was not damaged.

When news first broke out of the accident, the exact cause had remained a mystery. The U.S. Navy initially reported that the submarine had hit an unknown "object" while it was on patrol in "international waters."

The U.S. Navy periodically challenges China's contested territorial claims to islands, reefs, and outcrops in the region. The South China Sea is one of the most contested and commercially important waters on the planet.

China claims practically the whole territory under its contentious nine-dash line, and in recent years has constructed artificial islands and military bases. Malaysia, Brunei, Vietnam, the Philippines, and Taiwan all claim sections of the contested sea.