A major disaster occurred when a ferry with 462 people on board including high school students on a school trip to Jeju Island sank off the coast of Jindo, South Jeolla Province leaving six dead and 280 missing. It was revealed that the ferry operator had not taken proper emergency measures, telling the passengers to "stay put" for thirty minutes despite that the boat was sinking.

At around 8:58 a.m. on April 16, the Coast Guard received a report that Sewol, a 6,825 ton ferry operated by Cheonghaejin Marine Company was sinking 3 kilometers southwest of Gwanmaedo in Jindo-gun, South Jeolla Province. Gang (58), a passenger who was rescued said, "At around 8:30 a.m. when we were having breakfast, there was a sound like the bottom of the boat had scraped something and then the boat began to gradually tilt."

At the time of the report, the ferry had tilted about 20 degrees to the left, but at around 10:30 a.m. it completely overturned and sank. The Coast Guard announced that as of 1:00 a.m. on April 17 six people had died including Bak Ji-yeong (27), a crew, and Jeong Cha-wung (17), an eleventh grader at Danwon High School in Ansan, Gyeonggi Province. They also added that 280 people who remained in the cabin had not been able to escape and were trapped in the sunken ship.

One girl from Danwon High School who was on board the ship for her school trip tearfully said, "They told us to stay put with our life vests on. So for thirty minutes we just held on to the railings in the corridor without thinking about evacuating the ship. But then suddenly, the water started to pour in, and so we ran out. The situation was so urgent that I don't even remember how I was rescued."

When the accident occurred, related agencies such as the Coast Guard, Navy, and the West Sea Fisheries Supervision Office sent more than 200 boats including patrol boats and naval ships and 15 helicopters to the site and embarked on a rescue operation. The Jindo fishermen also stopped their work and more than 60 boats helped in the rescue operations.

Coast Guard and Navy divers entered the cabin in order to find and rescue survivors, but faced difficulties due to the strong currents, maze-like structure inside the boat, and the darkness.

The Coast Guard believes it is likely that the ferry collided with a reef based on the statements by survivors who said they heard the sound of a collision coming from the front of the boat. The ferry drifted 5.1 km to the northwest immediately after the accident and is now sitting on a mud flat near Byeongpungdo where the water is 38 m deep.

The ferry had departed from the Incheon Ferry Terminal at 9 p.m. on April 15 and was heading for Jeju Island. There were a total of 462 people on board the ferry including 325 students and 14 teachers from Danwon High School on a 4-day school trip to Jeju Island, travel agents, crew, and other passengers.

The rescued students and passengers were moved to the Jindo Gymnasium after arriving at Paengmok Port in Imhoe-myeon, Jindo-gun and are now resting after receiving a supply of clothes, blankets and food. More than fifty people who received injuries such as fractures and burns are receiving treatment in six hospitals including Jindo Hankook Hospital and Haenam General Hospital. The deceased have been placed in Mokpo Hankook Hospital.