韩国继续搜寻沉没渡轮幸存者

South Korea continues desperate efforts to save some 300 people still missing a day after a ferry carrying about 470 passengers sank off the country's southwestern coast.

Most of the passengers were high school students and their teachers on an excursion. At least six people have been confirmed dead so far and about 180 have been plucked from the sunken vessel or the waters around it. A U.S. Navy ship stands ready to assist in the massive rescue operation.

Coast Guard, military vessels, helicopters and divers have been searching for survivors of the sunken ferry. Distraught parents gathered along the coast hoping for the return of their children and bracing for the worst. This mother of an 18-year-old student describes her shock at hearing that the ship has sunk.

"I felt like my heart stopped," she said. "I can't describe the feeling with one word. I was too shocked. I can't even talk about it.

It was not immediately clear why the Sewol ferry listed heavily to one side and capsized in calm waters off South Korea's southwest coast. Some survivors reported hearing a loud noise before the vessel started sinking.

Some of the passengers who jumped into the water as the ferry went down were picked up by commercial vessels. Rescue teams balanced on the sinking hull to pull some people from cabin windows and helicopter crews plucked others from the deck.

Survivors were taken to a temporary shelter where they were wrapped into blankets and received medical assistance.

"I held a handrail and moved toward the right side of the ferry to ride a helicopter as water kept coming in," said Kim.

Many others were not so lucky and remained trapped in the ship's cabins.

An elderly woman says she followed the crew's instructions to stay in place.

"I was keeping still without making any movements," she said. "There was an announcement that we should not move.

The Sewol sank Wednesday morning near the island of Jindo. Officials from the company that owns the ship apologized for the accident. During a meeting with emergency officials, South Korean President Park Geun-hye expressed her sympathies to those affected.

"I think it is truly tragic that the students who were going on a field trip and the passengers were involved in such an unfortunate accident," said the president.

The U.S. Navy's amphibious assault ship, USS Bonhomme Richard, is nearby and has helicopters and boats to help if needed. The large ship was on routine patrol in waters west of the Korean peninsula. Low water temperatures and fast currents worsened the situation overnight for any possible survivors.