A US defence official said there was flooding in three compartments of the Fitzgerald.
Two injured crew members, including the captain, have been airlifted from a US Navy destroyer that collided with a merchant ship off the coast of Japan, as a search is under way for seven missing sailors.
The navy said Commander Bryce Benson was taken to the US Naval Hospital in Yokosuka, the home base of the 7th Fleet. It says he was in a stable condition.
Navy chief Admiral John Richardson said US Navy, Japanese maritime defence vessels and the Japanese coastguard were working to stabilise the badly-damaged ship.
Japan’s coastguard believe the missing sailors were thrown into the sea or possibly trapped inside damaged sections of the destroyer.
TV footage showed heavy damage to the mid-right side of the USS Fitzgerald and a someone on a stretcher being lifted to a helicopter.
The navy said the Fitzgerald was damaged below the water line on its starboard side.
The Japan Coast Guard said it received an emergency call from Philippine-registered container ship ACX Crystal at around 2.20am local time on Saturday (6.20pm Friday BST) saying it had collided with the Fitzgerald south west of Yokusuka.
The Fitzgerald collided with the 730ft merchant ship 56 nautical miles from Yokosuka, a city south of Tokyo.
A US defence official said there was flooding in three compartments of the Fitzgerald.
Relatives of the US crew were anxiously awaiting news of their loved ones.
A relieved Rita Schrimsher of Athens, Alabama, whose family had been “nervous and scared and just praying”, later received a call from her grandson, sailor Jackson Schrimsher, 23, to say he was safe.
Ms Schrimsher tweeted: “Just heard the sweetest voice and saw a wonderful face. He’s okay. Thank you all for the prayers.”
After speaking to Jackson on Facetime, she said: “It could have been worse, so we’ re grateful.”
