HMS E41 collided with E4 on the surface during exercises off Harwick on 15 August 1916. Sixteen crewmembers were lost, but fifteen escaped including seven from the bottom. Six crew members trapped in the submarine as she sank were able to escape by waiting under the conning-tower until the air pressure building up as the submarine sank blew the hatch open and allowed them to float to the surface. Chief Petty Officer William Brown was left behind, but was eventually able to escape from the engine room after an hour and a half in the sunken submarine