TOKYO: The US Navy will hold a memorial service Tuesday for seven sailors killed in a collision with a cargo ship off the coast of Japan this month.
The private gathering is being held at a naval base in Yokosuka, south of Tokyo, the home port of badly damaged destroyer, the USS Fitzgerald, a navy spokesman said.
The sailors' relatives, their 300 shipmates on the guided-missile destroyer and US military officials are expected to attend the service Tuesday morning, as a probe into the cause of the deadly accident continues.
Investigators have been analysing exactly what happened in the early hours of June 17, when the warship collided with the Philippine-flagged ACX Crystal in a busy channel not far from Yokosuka, a gateway to container ports in Tokyo and nearby Yokohama.
The sailors, aged 19 to 37, were found by divers in flooded sleeping berths a day after the collision tore a huge gash in the side of the Fitzgerald.
Japanese investigators have interviewed the Filipino crew of the 222-metre (730-foot) cargo ship, while the US authorities are also probing the crash.
Rear Admiral Brian Fort has been appointed to lead the US investigation, the navy has said.
There have been around 30 ship collisions over the past decade in the area, including a 2013 incident in which six Japanese crew died, according to the Japan Coast Guard.
Adding to the questions surrounding the crash, ACX Crystal's crew -- who were not injured -- apparently took nearly an hour to report the collision.
The Japan Coast Guard initially said the crash happened at 2:20 am Saturday (1720 GMT Friday) based on when it was reported by the Crystal's crew.
But they later told Japanese investigators the incident actually happened almost an hour earlier at 1:30 am.
Authorities are also investigating why the cargo ship made a sudden turn at about 1:30 am, and a sharp turn after it reported the accident around 2:20 am.