The Navy says it remains uncertain how long it will take to gain access to the spaces inside the damaged destroyer in order to methodically search for the missing crew members. "A significant part of the crew was sleeping", he told reporters. The USS Fitzgerald could have foundered, or even sunk, but for the crew's desperate efforts to save the ship, he said.
The water flow into compartments that were berthing areas for 116 of the ship's crew was "tremendous", he said, adding that "there wasn't a lot of time in those spaces that were open to the sea".
The Navy said incident is now under investigation.
Aucoin said the final toll was not being released "out of respect for their families".
Acting Secretary of the Navy Sean Stackley says the Navy is deeply saddened and promised a full investigation into a collision between a destroyer and a container ship off Japan that killed seven sailors.
He also praised their colleagues for saving the USS Fitzgerald from further damage and bringing it back to port. They had to fight the ship to keep it above the surface.
The bodies were found in flooded compartments Sunday after it returned to the base in Yokosuka with the help of tug boats.
He is in stable condition, the Navy said.
Cmdr. Bryce Benson, the destroyer's captain, was airlifted from the ship's deck to the U.S. Naval Hospital in Yokosuka with a head injury.
The badly damaged destroyer was towed to the 7th Fleet's home base in Yokosuka, Japan. Two other crew members suffered cuts and bruises and were also flown out by helicopter.
About 200 sailors were aboard the ship at the time of the collision. Maritime rules suggest vessels are supposed to give way to ships on their starboard. Most congestion occurs in the early hours of the day, and fast currents make it a tricky area that requires experience and skill to navigate.
At the time of the crash, the Crystal was weighted down by a 29,000-ton cargo load.
Container ships like the Crystal have bulbous bows under the waterline and that portion of the cargo vessel plowed into the U.S. warship. Photos of the Crystal showed damage to its bow. Many scratches were also seen in the frontal area.
Shipping data in Thomson Reuters Eikon shows that the ACX Crystal, chartered by Japan's Nippon Yusen KK, made a complete u-turn between 12:58 a.m. and 0246 a.m. local time on June 17.
The Japanese coast guard was on the scene and a United States official said U.S. tugboats and other Navy assets, including aircraft, were on the way.
The coast guard questioned crew members of the ACX Crystal, and is treating the collision as a case of possible professional negligence, said Masayuki Obara, a regional coast guard official.
Abe said in his message to Trump on Sunday, "We are struck by deep sorrow", expressing condolences and sympathy "straight from my heart" to the victims and the injured.
President Donald Trump sent a message of encouragement to the crew on Saturday morning.
Abe wrote, "I express my heartfelt solidarity to America at this hard time", praising USA servicemen in Japan under the allies' bilateral security pact.
Other injured sailors are being assessed, the Navy said.
Jennifer Adkison of Granbury, Texas, whose 20-year-old son, Bruce Adkison, a fifth-generation sailor, survived the collision, said in a Facebook message that families are grieving for those who died and trying to get clothing and other items to survivors who lost all their possessions.