Yes,
I do get killed in 1940 (not in 39 though) usually by overconfidence, but at least once where 3 escorts teamed up on me and did the whole 1 pings, 1 drop DCs and the other circles your position just to distract you and they keep switching roles, then when they have you located they'll just pound you and pound you until you either implode or are forced to surface with heavy damage, then they either ram you or blast you with their guns....
Beware the Black Swans !!!