Some remains have been found in the search for the 10 sailors reported missing in the collision Monday of the US destroyer John S. McCain and an oil tanker near Singapore, an admiral told reporters on Tuesday.
Ships and planes have been scouring seas east of Singapore since the early hours of Monday morning local time, when the warship and tanker crashed, injuring five other sailors.
Navy and Marine Corps divers will also assess the extent of damage to the warship, which is docked at a Singapore naval facility, according to a statement from the US Navy.
The incident has prompted the US Navy to order a rare, one-day operational pause in response to the collision, which was the latest in a string of accidents involving Navy vessels -- with four occurring in Asian waters this year alone.
"This trend demands more forceful action," Chief of Naval Operations Adm. John Richardson said.
At least seven vessels from the Malaysian and Singapore navies, plus military aircraft from the USS America, are involved in the search in the waters east of the Straits of Malacca and Singapore, where the collision took place. The area is near one of the world's most congested shipping lanes.
A Malaysian official said Monday the sea in the area was "quite rough," with waves up to one meter (three-feet) high.
One of the missing seamen was named as Petty Officer Logan Palmer in a Facebook post by US Congressman Rodney Davis, who said that he was in touch with the missing man's family.
Of five sailors injured in the crash, four were airlifted to a Singapore hospital by a Singaporean air force helicopter.
What caused the accident?
The warship suffered a steering failure as the warship was beginning its approach into the Strait of Malacca, causing it to collide with a commercial tanker Monday, a US Navy official told CNN.
The official said it was unclear why the crew couldn't utilize the ship's backup steering systems to maintain control of ship.
Earlier, another US Navy official told CNN there were indications the destroyer experienced a loss of steering right before the collision, but steering had been regained after the collision.
The USS John S. McCain has been towed to Singapore's Changi Naval Base. The much larger ship it collided with, the Alnic MC, a 600-foot, Liberian-flagged oil and chemical tanker, was towed to Singapore's eastern anchorage for inspection.
Monday's collision bears a resemblance to an incident in June involving the USS Fitzgerald, which collided with a container ship off the coast of Japan and led to the deaths of seven US sailors.
In addition, the USS Lake Champlain hit a South Korean fishing boat in May and the USS Antietam ran aground off the coast of Japan in January.
Lawmakers and defense analysts have warned that longer deployments for ships and less time and money for maintenance and training could be playing a role in the incidents.
A press release on the John S. McCain released last week said that the crew had completed 350 maintenance and repair jobs while at sea. At least 100 of those jobs were classified as "depot-level" jobs that would usually be conducted at a ship yard.
"We are not letting this deployment eat away at our material readiness," said Cmdr. Jessie Sanchez, the executive officer of McCain. "We continue to maintain our upkeep, so that when we come back, we are just as good if not better than when we left."
While there was no indication the collision was intentional nor was there evidence that the ship was the target of a cyberattack, investigators would not discount these possibilities, Richardson told reporters.
"We are taking a look at all (options) as we did with the (USS) Fitzgerald as well," he said.
What actions are being taken?
While the cause of the USS McCain crash is still to be determined, the spate of accidents suggests there could be a more systemic issue.
"This is the second major collision in the last three months, and is the latest in a series of major incidents, particularly in the Pacific theater," Richardson said, as he announced the operational pause.
The US has ordered a "comprehensive review," which Defense Secretary James Mattis said "will determine any of the causal factors, to determine what's going on -- both immediate contributors to this incident but also any related factors."
The review will take place over a week in a series of 24-hour periods, during which onboard actions, as well as leadership and operational procedures, will be examined.
Speaking at the Osan Air Base in South Korea, Adm. Harry Harris, commander of the US forces in the Pacific, said that the operational pause is "important" but added that pause "would not have an effect" on the US' ability "to defend our nation and our allies."
The McCain, named for Sen. John McCain's father and grandfather both of whom were Navy admirals, is one of 84 US warships equipped with the Aegis missile defense system, which has been touted as a possible counter to any North Korean missile launch.
Retired Navy Rear Adm. John Kirby, a CNN diplomatic and military analyst, said the Navy will look at a number of factors to try to understand if there's a systemic problem.
"They'll look at the quality of leadership at all levels, the amount and the quality of training that commanders have been able to get done, shipboard watch-standing procedures and qualifications, and system and equipment readiness," Kirby said.
"I suspect they will also want to consider the degree to which the budget uncertainty of the last few years has likewise affected any of those factors."
Criticism in Chinese press
An unbylined opinion piece in the state-run China Daily newspaper criticized the recent spate of accidents, saying the US Navy was becoming "a hazard in Asian waters."
"It may be hard for people to understand why US warships are unable to avoid other vessels since they are equipped with the world's most sophisticated radar and electronic tracking systems and aided by crew members on constant watch," the piece, published in the English-language daily said.
Calling the Navy a "dangerous obstacle" and an "increasing hindrance to ships sailing in Asian waters," the opinion piece says there was "no denying the fact that the increased activities by US warships in Asia-Pacific since Washington initiated its rebalancing to the region are making them a growing risk to commercial shipping."
It adds that investigations into the cause of the June USS Fitzgerald collision "shed some light on the way US warships tend to sail without observing maritime traffic rules and the sloppiness of their crews."
The collision has also put a spotlight on a territorial dispute that has strained ties between Singapore and Malaysia for decades.