By Michael Pearson, Euan McKirdy and Stella Kim, CNN

(CNN) — Military dive teams worked the dark, cold waters of the Yellow Sea on Wednesday night in a desperate effort to find nearly 300 people who are missing after the ferry they were taking to a South Korean island resort sank with breathtaking speed.
Officials said four people were known dead and 164 had been rescued after the sinking of the ferry Sewol off the southwest coast of South Korea.
Another 292 people are missing, authorities said. Among the 459 people who were aboard the ship: 325 students and 15 teachers from Seoul’s Ansan Danwon High School heading to a four-day trip to Jeju, a resort island considered the Hawaii of Korea.
It was not immediately clear if the dead — three males and a female — were students or teachers, part of the 30-member crew or from the 89 other passengers on board the ferry.