MOKPO, South Korea — Koo Bon-hee could see the exit. For half an hour, as the doomed ferry filled with water and listed severely on its side, the crew told passengers to wait for rescuers.
With their breathing room disappearing, the 36-year-old businessman and some of the other passengers floated to an exit and swam to a nearby fishing boat. But 287 of the 475 people aboard — many of them high school students on a class trip — were still missing after the ferry sank Wednesday off the southern coast of South Korea. Nine were confirmed dead, 55 injured.
Early Thursday, divers, helicopters, and boats continued to search for survivors from the ferry, which slipped beneath the surface until only the blue-tipped, forward edge of the keel was visible. The high number of people unaccounted for — possibly trapped in the ship or floating in the chilly water nearby — raised fears that the death toll could increase drastically.
It was still unknown why the ferry sank, but the coast guard was interviewing the captain and crew.
The Sewol, a 480-foot vessel that can hold more than 900 people, set sail Tuesday from Incheon, in northwestern South Korea, on an overnight, 14-hour journey to the tourist island of Jeju. About 9 a.m. Wednesday, when it was three hours from Jeju, the ferry sent a distress call after it began listing to one side, according to the Ministry of Security and Public Administration.
Passenger Kim Seong-mok told broadcaster YTN that he felt the ferry tilt, then heard it crash into something. He said passengers were told to not move from their places, and that he never heard anything about evacuating.
He said he was certain that many people were trapped inside the ferry as water rushed in, the severe tilt of the vessel keeping them from reaching the exits.
Koo also criticized the crew’s efforts during the initial stages of the disaster, saying early misjudgments may account for the large number of missing.
‘‘The rescue wasn’t done well. We were wearing life jackets. We had time,’’ Koo, who was on a business trip to Jeju with a co-worker, said from a hospital bed in Mokpo, the nearest major city to the site of the accident, where he was treated for minor injuries. ‘‘If people had jumped into the water, they could have been rescued. But we were told not to go out.’’
Oh-Yong-seok, a 58-year-old crew member who escaped with about a dozen others, including the captain, said rescue efforts were hampered by the ferry’s severe tilt.
‘‘We couldn’t even move one step,” Oh said. “The slope was too big.’’
Student Lim Hyung-min told YTN that he and others jumped into the water wearing life jackets, then swam to a nearby rescue boat.
‘‘As the ferry was shaking and tilting, we all tripped and bumped into each other,’’ Lim said, adding that some people were bleeding. Once he jumped, the water ‘‘was so cold. . . . I was hurrying, thinking that I wanted to live.’’
Dozens of coast guard and navy divers searched for survivors around the Sewol’s wreckage a little north of Byeongpung Island.
Coast guard spokesman Cho Man-yong said 16 divers could not get inside the ferry Wednesday night because the current was too strong. The water was muddy and visibility poor, he said, but he said divers would try again Thursday morning.
After a briefing in Seoul, President Park Geun-hye of South Korea reaffirmed the search would continue.
‘‘We cannot give up,” he said. “We have to do our best to rescue even one passenger.’’
White House spokesman Jay Carney said the United States and its Seventh Fleet stood ready to assist, including the USS Bonhomme Richard, which was in the region.
The last major ferry disaster in South Korea was in 1993, when 292 people were killed.
Television stations broadcast live pictures Wednesday of the listing Sewol as passengers clambered over the side, jumped into the sea, or were hoisted up by helicopters. At least 87 vessels and 18 aircraft swarmed around the ferry.
The water temperature in the area was about 54 Fahrenheit, cold enough to cause signs of hypothermia after about 1½ hours of exposure, according to an emergency official who spoke on condition of anonymity because he was not authorized to speak to the media.
Lee Gyeong-og, a vice minister for the Public Administration and Security Ministry, said the ocean was 121 feet deep in the area.