Jindo, South Korea (CNN) -- An arrest warrant has been issued for the captain of the ferry that sank off the coast of South Korea, an accident that killed 28 people and left nearly 270 missing.
Two other crew members also face arrest, a spokesman for the joint prosecutor and police investigators said Friday.
The spokesman did not provide any further detail.
The cause of the accident still isn't known. But a Korean prosecutor said the captain, Lee Joon Suk, wasn't in the steering room when the ship started to sink; a third mate was at the helm.
"It is not clear where (the captain) was when the accident occurred, although it is clear that he was not in the steering room before the actual accident happened," state prosecutor Jae-Eok Park said Friday.
The captain was one of at least 179 people rescued soon after Wednesday's sinking.
In a tragic twist, one of those rescued, a high school vice principal who was on board the ferry along with more than 300 students, was found hanging from a tree, police said.
Kang Min Kyu, 52, vice principal of Ansan Danwon High School, was among the first survivors to be rescued.
Police said he apparently hanged himself with a belt from a tree near a gymnasium in Jindo, where distraught relatives of missing passengers have been camping out.
Meanwhile, divers raced to reach the hundreds of people still believed to be inside the ship.
Divers breached the hull of the sunken ferry Friday, and two managed to enter the second deck -- the cargo deck, the South Korean coast guard said. But rough waters forced them back out again. They didn't find any bodies in their brief search.
"The guide line that links the sunken ship and the rescue vessel has been cut off," the coast guard said. "Still, the entrance into the ship is open, and we plan to resume operation to enter the ship."
It's a race against time.
Hopes of finding the missing dimmed further when the entire boat became submerged Friday. Until then, part of the ship's blue-and-white hull was still poking out of the frigid waters of the Yellow Sea.
On top of that, divers must contend with fierce winds and rough waters.
"There are heavy currents in the area. So the vessel itself is not stable in the water. So you are, by default, putting divers at risk," U.S. Navy Capt. Heidi Agle told CNN's Wolf Blitzer. The U.S. Navy is assisting with the South Korean search.