SINGAPORE - US guided-missile destroyer USS John S. McCain collided with a tanker in waters near Singapore on Monday (Aug 21) morning, the second crash involving an American naval vessel in Asia in two months.
Its sister ship USS Fitzgerald collided with a Philippine-flagged cargo ship off the Japanese coast in June, resulting in the deaths of seven US sailors.
Search and rescue efforts are underway for 10 missing sailors. The injured US sailors have been transferred to Singapore for non-life threatening injuries. No crew on the tanker was hurt in the collision.
Here are seven key facts about the US warship.
1. Named after US war heros
The warship is named after Senator John McCain's father, John S. McCain, Jr and Senator McCain's grandfather; John S. McCain, Sr.
Both men were highly decorated naval officers who played key roles in the Pacific Theater during World War II.
The two men became the first father and son in naval history to both attain the rank of admiral.
Sailors refer to the ship as "Big Bad John", in reference to the fighting spirit of the ship's namesakes.
Senator McCain, who recently underwent brain surgery, said in a tweet that he and his wife "are keeping America's sailors aboard the USS John S. McCain in our prayers tonight - appreciate the work of search and rescue crews".
The destroyer's motto is "Fortune favours the brave".
2. History of warship
It was built in 1991 at Bath Iron Works in Maine and commissioned in 1994.
The ship has a crew of 23 officers, 24 chief petty officers and 291 sailors.
Four of the five crew members injured in Monday's collision have been transferred to Singapore for non-life threatening in juries. The fifth US sailor did not require any further medical attention.
3. A key asset in US naval forces
It belongs to the Arleigh Burke class of destroyers, whose key feature is the Aegis missile defence system.
The Aegis missile defence system that detects and intercepts ballistic missiles has been touted as a possible defence against the North Korean missile threat.
Japan's defence ministry and military officials have voiced concerns that the collision between a US Navy destroyer and a tanker on Monday may negatively affect the Japan-US security system regarding North Korea, reported Yomiuri Shimbun.
Destroyers can operate independently or as part of carrier strike groups, surface action groups, amphibious ready groups, and underway replenishment groups.
With the USS Fitzgerald now undergoing repairs after its collision with a container ship in June, and the USS McCain damaged in Monday's incident, there are questions over the US Navy's ability to keep up its patrols in the region. Both ships belong to the Japan-based destroyer squadron (DESRON) 15.
Asked whether the US Navy would need to bring forward other ships to maintain its strength, a spokesman for the Seventh Fleet told Reuters it was "way too early to know".
Not counting the USS Fitzgerald, the US Navy's 7th Fleet has six ships assigned to the so-called Ballistic Missile Defence (BMD) patrols, with half of those out on patrol at any one time.
4. Homeport in Yokosuka in Japan
USS McCain comes under the command of US' 7th Fleet, which is based in Yokosuka Naval Base in Japan's Kanagawa prefecture.
The base, which is located south of Tokyo, is also home to the nuclear-powered US aircraft carrier Ronald Reagan.
Since the Korean and Vietnam conflicts, the Yokosuka base continues to be the US' most important naval facility in the western Pacific.
An assistance centre has been set up for families at the base.
At any given time, there are about 5,070 ships and submarines, 140 aircraft, and approximately 20,000 sailors in 7th Fleet.
Ships from the 7th Fleet make more than 500 port visits to 25 countries every year.
5. Latest US warship to be hit in string of mishaps
The US navy has suffered four mishaps in the Pacific since the beginning of this year.
On May 9, the guided-missile cruiser USS Lake Champlain was struck by a small fishing boat off the Korean Peninsula.
In late January, the guided-missile cruiser USS Antietam ran aground while trying to anchor in Tokyo Bay.
USS Fitzgerald collided with a Philippine-flagged cargo ship off the Japanese coast in June, resulting in the deaths of seven US sailors.
All three US warships and USS McCain are equipped with the Aegis missile defence system.
Bryan McGrath, a retired US Navy commander who was the skipper of the USS Bulkeley destroyer, said it was "hard to tell whether these are coincidences or there is something deeper."
"We just don't know yet," he told Japan Times. "But I have every confidence the navy will get the facts."
6. Carried out 'freedom-of-navigation' patrols in South China Sea
The 154m long McCain carried out a freedom-of-navigation operation in the South China Sea on Aug 10.
The Star and Stripes website, quoting a Navy official who spoke on condition of anonymity, said it sailed within 6 nautical miles of Mischief Reef in the disputed Spratlys, in "a challenge to the country's (China's) vast territorial claims in international waters".
It was the third time this year that a US warship cruised within 12 nautical miles of a China-claimed land mass, showing the Americans do not recognise Chinese claims on the islands, said the Stars and Stripes article.
7. Took part in biggest joint US-Australia drills
USS McCain joined four Royal Australian Navy ships for four days of high-end warfare exercises off the coast of Darwin in July.
The drills, the maritime component of Talisman Saber, saw the warships engage in manoeuvres to detect, track and engage surface, submarine and air targets. Talisman Saber, a biennial exercise, is the biggest war games held in Australia.
The exercises, said the militaries provide a realistic and challenging training environment to practise "readiness and inter-operability" between the two nations, while enhancing security and stability in the Indo-Asia-Pacific region.