Four people are dead and nearly 300 are missing after a ferry sank off the coast of South Korea. Most of the 459 people on board were high school students en route to a tourist island called Jeju.

The Coast Guard arrived within an hour of the captain’s distress call at 9 a.m. local time on Wednesday.

More details from FoxNews.com:

Lee Gyeong-og, a vice minister for South Korea's Public Administration and Security Ministry, said the 459 people included 30 crew members, 325 high school students, 15 teachers and 89 non-student passengers. 

Kang Byung-kyu, a government minister, said two of the dead were a female crew member and a male high school student. He said a third body was also believed to be that of a student. A coast guard officer confirmed a fourth fatality, but had no immediate details about it. 

He said 164 people were rescued; 55 of them were injured. He said 284 people were missing, likely either trapped inside the ship or floating in the ocean. 

The high number of people unaccounted for -- likely trapped in the ship or floating in the ocean -- raised fears that the death toll could rise drastically.

"We cannot give up," said South Korean President Park Geun-hye, after a briefing in Seoul with officials. "We have to do our best to rescue even one passenger."

Media photos showed wet students, some without shoes, some wrapped in blankets, tended to by emergency workers. One student, Lim Hyung-min, told broadcaster YTN from a gym on a nearby island that he and other students jumped into the ocean wearing life jackets and then swam to a nearby rescue boat.

"As the ferry was shaking and tilting, we all tripped and bumped into each another," Lim said, adding that some people were bleeding. Once he jumped, the ocean "was so cold. ... I was hurrying, thinking that I wanted to live."

In an update on America’s Newsroom, GRN reporter Jason Strother said that it may take days and possibly weeks to get the boat back to land. 

Strother reported that there are concerns that bad orders may have contributed to the death toll, including telling people to stay seated as the boat tilted.

South Korean naval forces sent divers into the boat to look for survivors in the cabins. The U.S. Navy is sending the USS Bonhomme Richard, which was on a routine patrol off the west coast, to assist in the search and rescue.

The boat had the capacity to hold about 900 people. It's a common form of transportation in the region and has a low record of accidents, Strother reported.