On the morning of 28 April, 1942, the D-Day invasion rehearsals was blighted when a convoy of follow-up troops was attacked by nine German E-boats in Lyme Bay. As a result of official embarrassment and concerns over possible leaks just prior to the real invasion, all survivors were sworn to secrecy by their superiors. Ten missing officers involved in the exercise had BIGOT-level clearance for D-Day, meaning that they knew the invasion plans and could have compromised the invasion should they have been captured alive. As a result, the invasion was nearly called off until the bodies of all ten victims were found. Read more