It most likely struck something in the water , said Peter Boynton , a retired U.S. Coast Guard captain . South Korean oceans ministry : The North has been using the waters of the Yellow Sea as a fishing ground for more than two decades and is believed to have used it in recent years to transport coal from its mines on the Some passengers reported hearing a bang before the ship sank . The ship had traveled through fog , but conditions were clear at the time of the accident . The most immediate danger to passengers is hypothermia .
South Korean oceans ministry : The North has been using the waters of the Yellow Sea as a fishing ground for more than two decades and is believed to have used it in recent years to transport coal from its mines on the Some passengers reported hearing a bang before the ship sank . The ship had traveled through fog , but conditions were clear at the time of the accident . The most immediate danger to passengers is hypothermia .