She was depth charged by an unidentified British vessel and was forced to dive to 100 meters ( 328 feet ) to escape the attack .
Prior to her sinking , U-39 was attacked in the North Sea on 10 September while en route to the British Isles .
U-39 was depth charged by an unidentified British vessel and was forced to dive to 100 meters ( 328 feet ) to escape the attack .
Prior to her sinking , U-39 was attacked in the North Sea on 10 September while en route to the British Isles .