Police say a high school vice principal rescued from the South Korean ferry that capsized Wednesday has committed suicide.
The news comes as hopes dim of finding any of the nearly 270 people missing from the Sewol ferry alive.
The 52-year-old vice principal, Kang Min-kyu, had been the leader of a group of at least 325 students traveling on the ferry on a school trip.
Police say he was found Friday hanging by his belt from a tree near a gym on the island of Jindo where survivors and relatives of those missing have been staying.
He is said to have left a suicide note saying he felt guilty for being alive.
The official death toll from the disaster is 28, with 179 survivors, but many more are presumed dead. Of the hundreds of others still missing, many are high school students.
Authorities have not established the cause of the disaster. But some survivors report hearing a loud impact noise before the vessel rolled onto its side and began sinking.
Heavy fog was reported in the area on Tuesday evening, but it is not known whether that was a contributing factor.
The captain of the ferry, which was carrying 475 people when it capsized off South Korea's southern coast, has also come under scrutiny.
Investigators say Captain Lee Joon-seok was not at the helm when disaster struck.
Officials said Friday a junior officer was at the helm when the ferry is thought to have made a sharp turn before tilting to the side and sinking.
The coast guard has also said it is investigating reports that the captain was among the first to abandon the vessel.
The students on the ferry were from Danwon High School near Seoul. They were traveling to the popular resort island of Jeju for a four-day field trip and sightseeing.
Many passengers said they were initially told to stay in their seats and not try to escape, a development that outraged many families of the victims.
Rescuers have fought strong currents and murky waters in their search for the missing.
U.S. President Barack Obama has sent his condolences to the families and says he will pay tribute during a visit to South Korea next week.