The bow hit the bottom at a speed of about 20 knots (10 metres per second), digging about 60 feet (20 m) deep into the mud, up to the base of the anchors. The impact bent the hull in two places and caused it to buckle downwards by about 10° under the forward well deck cranes and by about 4° under the forward expansion joint. When the bow section hit the sea bed, the weakened decks at the rear, where the ship had broken apart, collapsed on top of each other.[80] The forward hatch cover was also blown off and landed a couple of hundred feet in front of the bow, possibly due to the force of water being pushed out as the bow impacted the bottom.[82]