The collision earlier this month between two U.S. Navy vessels in the Strait of Hormuz left a surface ship with a gaping hole in its fuel tank and caused a submarine to roll about 85 degrees, U.S. Navy officials said Monday.

The March 20 collision between the amphibious assault ship USS New Orleans and the fast-attack nuclear submarine USS Hartford slightly injured about 15 sailors aboard the sub, and spilled oil from the ship into the strait.

The Navy has launched two formal investigations to determine why the vessels collided and who might be at fault for the collision.

The Judge Advocate General Manual Investigation is being led by Capt. Craig Kleint, the Dock Landing Ship Class Squadron commodore, said Lt. Nathan Christensen, a spokesman with U.S. Naval Forces Central Command/5th Fleet.

A senior submarine officer, a Navy captain whose name is not being publicly released until the end of the probe, will head the safety investigation, Christensen said.

No action has been taken against either of the vessels’ commanding officers, Christensen said. The Hartford is commanded by Cmdr. Ryan Brookhart and the New Orleans by Cmdr. Scott Davies.

Investigators believe the Hartford, submerged at the time of the incident, rolled about 85 degrees during the collision, which might have caused or contributed to the sailors’ injuries.

Despite the roll, engineering investigators confirmed to Navy officials that the submarine’s nuclear propulsion was unaffected in the crash. However, according to a Navy news release, the Hartford sustained damage to its periscope and sail — the tower-like structure that juts from the top of the submarine — and the port bow plane, or the wing on the sail’s left side.

As a result of the March collision, the New Orleans sustained a "very sizable" 16-by-18 foot hole in a fuel tank, and two damaged ballast tanks, Christensen said. No sailors or embarked Marines were injured.

The collision caused 25,000 gallons of diesel fuel to leak into the Persian Gulf from the New Orleans.

Both vessels, though damaged, were able to sail under their own power and arrived in Bahrain on March 21, where crews assessed the damage and began repairs.

The Navy has given investigators a deadline of 30 days from March 24, Christensen said. Final reports will be submitted to Naval Forces Central Command.

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