A hunt for survivors stretched into the night as search teams looked for the 10 US sailors who went missing after their warship collided with an oil tanker in the Singapore Strait.
The ship, based in Japan, was on its way to Singapore when it collided with the tanker more than three times its potential weight.
About 250 personnel from various Singapore agencies, including the Maritime and Port Authority of Singapore (MPA), which is leading the operations, the Republic of Singapore Navy (RSN) and Singapore Police Coast Guard, were deployed to the site.
The guided-missile destroyer USS John S. McCain - named after the father and grandfather of former US presidential candidate John McCain, who were both admirals - collided with Alnic MC at 5.24am.
A four-nation search effort, with at least 15 ships and helicopters from Singapore, the United States, Indonesia and Malaysia, is being carried out north of Pedra Branca.
Footage showed a vast hole pierced through the left rear of the US ship, which is based in Yokosuka, Japan.
Singapore forces were activated to help as the damaged US ship made its way - escorted by the Singapore navy - to Changi Naval Base, where it is being assessed.
The Liberian-flagged merchant ship, which was reportedly carrying almost 12,000 tonnes of fuel, had arrived at Changi's eastern anchorage to be further assessed. None of its crew was hurt and there was no oil spill, its owner said last night.
Apart from the 10 who are missing, five US sailors were injured. Four of them were evacuated by a Singapore Armed Forces Super Puma helicopter, which landed on the lawns of Singapore General Hospital, where they are believed to be warded. The fifth did not need further medical attention.
MPA has asked passing vessels to keep a lookout for any persons in the water. Singapore also accepted an offer of assistance from the Indonesian authorities, who deployed a helicopter to search the northern coastline of Bintan Island, MPA said.
The US also deployed its own assets to take part in the ongoing search and rescue effort.
Separately, Malaysia has deployed its own vessels to the area. It claimed the accident occurred in its area, which is at odds with Singapore's statement that the collision happened in its waters.
Questions also arose as to how the accident happened, especially since both vessels would have been equipped with the latest monitoring systems to avoid such incidents.
This is the second accident involving the US Navy's 7th Fleet in recent months. In June, seven sailors died when the USS Fitzgerald collided with a container ship off Japan.
MPA will look not just at the causes of the accident but also at any gaps that might exist in Singapore's vessel-monitoring system, experts said. This is critical as the Singapore Strait is one of the world's busiest sea lanes, they added.
But for now, the focus is clear. Captain Elizabeth Zimmermann, a spokesman for the US Navy, told The Straits Times: "We are focused now on finding our missing sailors."
Prime Minister Lee Hsien Loong, noting that the collision happened in Singapore waters, posted on Facebook: "My thoughts are with their families."
US Navy Secretary Richard Spencer said on Twitter: "I want to express my appreciation to the Government of Singapore for their swift support and assistance during this time of need."