Initial inspections by divers show that the water ingress was caused by damage to one of the stern thrusters. Thrusters are used for improving the vessels manoeuvrability and consist of a shaft tunnel fitted with a propeller delivering sideways thrust. It is now known that several propeller blades have broken off and there is severe damage to the propeller mounting, resulting in a crack in the forward stern thruster tunnel which caused the ingress of water.
The water flooded the engine room which consequently led to the loss of main engine power, and Emma Maersk was towed to the quay at Suez Canal Container Terminal.
http://www.maerskline.com/link/?page=news&path=/news/story_page/13/Emma_Maersk