Ship
© U.S. Navy / ReutersThe U.S. Navy Arleigh Burke-class guided-missile destroyer USS Fitzgerald returns to base after a collision off Yokosuka.
A US warship struck by a Philippines container ship in Japanese waters failed to respond to warning signals or take action before the collision took place, according to a report from the cargo ship's captain.

The Philippines ship ACX Crystal signaled to the USS Fitzgerald with flashing lights after the US warship "suddenly" changed course to one crossing the container ship's path, Captain Ronald Advincula's report to Japanese ship owner Dainichi Investment Corporation states, according to Reuters.

The container ship steered to avoid the warship, but hit the Fitzgerald 10 minutes later, according to the report.

The US Navy has declined to comment on the report, and Reuters was unable to independently verify the captain's account.

Seven US sailors were killed in the crash, which tore a gash below the Fitzgerald's waterline. The incident represents the largest loss of life on a US Navy vessel since 2000, when the USS Cole was bombed in Yemen's Aden harbor.

The deadly incident has resulted in six investigations. Among those are two internal hearings by the US Navy and a probe by the US Coast Guard, on behalf of the National Transportation Safety Board.

The Japan Transport Safety Board, the Japanese Coast Guard, and the Philippines government are also conducting investigations.

The probes will hear witness testimony and examine electronic data to determine exactly what took place. They will also examine the amount of time it took for the cargo ship to report the collision, with previous reports stating that the ACX Crystal took nearly an hour to call it in.

In his report, Advincula said there had been "confusion" on the cargo ship's bridge, and that the vessel turned around and returned to the collision site after continuing for six nautical miles (11 kilometers).