Updated

U.S. military investigators who examined a collision earlier this year between two Navy vessels in the Persian Gulf say the accident was preventable and that some submarine crew members habitually fell asleep and spent too much time away from their stations.

A Connecticut newspaper, The Day of New London, reported the findings after obtaining a heavily redacted report through the Freedom of Information Act.

The Navy investigation places the blame on the USS Hartford's "ineffective and negligent command leadership."

The USS Hartford, a submarine based in Groton, Connecticut, collided with the USS New Orleans, a Navy amphibious ship, on March 20 in the Strait of Hormuz. It caused a fuel leak and minor injuries to 15 sailors.