The US Navy says a nuclear submarine crashed in the Federated States of Micronesia because its crew were using the wrong undersea chart.
One sailor was killed an 97 others injured in January when the USS San Francisco crashed near the Caroline Islands.
The US Pacific Fleet department of public affairs says the submarine hit an undersea mountain that didn't appear on the chart that was being used for navigation at the time.
The 124-page report into the incident says the grounding could have been avoided and better navigation practices may have prevented loss of life.
The captain, Kevin Mooney, was relieved of his command in February and the USS San Francisco is now being repaired in Guam.