The USS Fitzgerald, which is listing after suffering severe damage on the starboard side in a collision with a container ship off Izu Peninsula, is towed to Yokosuka Port in Kanagawa Prefecture on June 17. (Kotaro Ebara)

The Japanese Coast Guard on June 18 called off its search for missing U.S. sailors following a deadly collision between an Aegis-guided U.S. Navy destroyer and a vast container ship of Filipino registry off Izu Peninsula.

But it will likely have a hard time investigating the cause of the accident, which occurred in Japanese waters on the early morning the previous day, due to the Japan-U.S. Status of Forces Agreement.

The SOFA stipulates that the U.S. military has the “primary right” to jurisdiction over its service members and American civilian workers who have been involved in crimes or accidents while on duty.

The 8,315-ton USS Fitzgerald was badly damaged around the center of its starboard side after the ACX Crystal, which weighs 29,060 tons, collided with the warship around 1:30 a.m. on June 17.

The container ship suffered damage at the front of its portside.

Coast Guard investigators interviewed the captain and other Filipino crew members of the ACX Crystal on suspicion of endangering traffic through negligent conduct in breach of duty of care.

The U.S. Navy in Japan, which called off its search for those missing inside the destroyer, promised to cooperate in the investigation if necessary.

Although it was initially reported that seven U.S. sailors were unaccounted for and three were injured, the U.S. Navy in Japan announced June 18 that the bodies of several sailors were discovered inside the vessel.

The bodies were found in living quarters housing 116 crew members, which were submerged after the collision.

At a news conference in Yokosuka, Vice Adm. Joseph Aucoin, commander at the U.S. Navy's 7th Fleet, would not confirm how many bodies were found.

The Navy ferried the bodies to U.S. Naval Hospital Yokosuka in Kanagawa Prefecture for identification.

Yoji Koda, a former commander of a Maritime Self-Defense Force ship, who is well-versed in the architecture of vessels, said it is not surprising that a warship can suffer significant damage in a collision.

“A warship is built with light, steel plates to boost its speed,” he said. “Even an Aegis-equipped vessel can be damaged extensively if its ‘flank’ was hit.”

The 3rd Regional Coast Guard Headquarters, which has jurisdiction over the accident that occurred about 20 kilometers off Cape Irozaki, said it was alerted to the collision by the container ship around 2:25 a.m.

None of the ACX Crystal's 20 crew members was injured.

The container ship, operated by Nippon Yusen KK, a Japanese company, was sailing to Tokyo after leaving Nagoya Port. The U.S. vessel was engaged in regular operations, according to the U.S. Navy in Japan.

According to the Coast Guard, the area where the accident occurred is known for heavy ship traffic after dark and before dawn to be in time for loading and unloading at ports in Tokyo Bay.

Three collisions involving a large vessel occurred in this area during the past five years.

"We sometimes end up noticing a vessel at a close distance no matter how vigilant we are at night," said a senior MSDF official.

In 2013, six crew members of a Japanese cargo ship died in a collision with a container ship with foreign registry in waters south of Tokyo.

The June 17 accident came after the International Maritime Organization designated a recommended sea route requiring navigation to the right in waters northeast to the accident site.

The route was expected to be marked on the sea chart under the decision made by the IMO this month.