South Korea’s authorities have indicted the master and three crew members of the ferry that sank last month for homicide through gross negligence, a crime punishable by death.
Sewol capsized and eventually submerged on a routine journey from Incheon to Jeju Island, killing 281 of the 476 passengers on board.
Rescuers continue to search for 23 missing people. Many of the casualties were children and their teachers on a school trip.
South Korean prosecutors told reporters in Seoul that the 69-year-old master Lee Joon-seok, the first and second officers and the chief engineer fled the vessel as hundreds of passengers remained on board.
The four have been accused of abandoning the ship without trying to evacuate the passengers, Yonhap News Agency reported.
Prosecutors also charged another 11 crew members for negligence because they escaped off the ship before many passengers.
Sewol, which lost part of its capability to maintain stability after remodelling work to add capacity, was massively overloaded and had insufficient water in its ballast tanks when the incident occurred, according to prosecutors.
When the ship sailed into strong currents, Capt Lee left navigation work to the third officer and the crew made a sharp turn of 15 degrees.
That was why Sewol listed rapidly and sank, prosecutors said.
Last week, South Korean authorities arrested the chief executive of ferry operator Cheonghaejin Marine, whose business licences are being revoked.
Prosecutors are also seeking to detain some members of the family that owns Cheonghaejin Marine, including one based in the US.
The South Korean government has faced strong criticism for not launching rescue operations in a timely manner, prompting president Park Geun-hye to offer a public apology and her premier to resign.
The investigation has also put the roles of Korean Register and Korean Shipping Association as industry monitoring bodies under the spotlight.
At the end of April, KR chairman Chon Young-Kee resigned “to ease the pain and sorrow of the Korean people and the families who lost their loved ones onboard Sewol”, the class society said.