WASHINGTON — A federal judge has ordered the U.S. Navy to begin releasing unclassified documents related to a submarine that imploded 57 years ago.

U.S. District Judge Trevor McFadden ordered the Navy on Feb. 10 to review 300 pages of documents per month starting in April, the Portsmouth Herald reported Tuesday.

There are about 3,600 identified pages of records concerning the USS Thresher, which was built at the Portsmouth Naval Shipyard in Kittery, Maine, that are set to be released before May 15, with a rolling production every 60 days.

Nearly 130 lives were lost April 10, 1963, when the Thresher sank 8,000 feet to the seafloor after conducting deep-dive exercises 220 miles off Cape Cod.