The stern of the ship, which measures about 350 feet (105 m) long, was catastrophically damaged during the descent and landing on the sea bed. It had not fully filled with water when it sank, and the increasing water pressure caused trapped air pockets to implode, tearing apart the hull. It was loud enough that multiple survivors reported hearing explosions about ten seconds after the stern had sunk beneath the waves.[citation needed] Data from a sonar map made during a 2010 expedition showed that the stern rotated like a helicopter blade as it sank.[91]