This day in 1944, over 700 American servicemen are killed during a large-scale rehearsal for the D-Day landings, when communication problems resulted in friendly fire and Allied ships were spotted by German E-boats.

It took families decades to figure out the truth. #WW2

• 1944 – World War II: Nine German E-boats attacked US and UK units during Exercise Tiger, the rehearsal for the Normandy landings, killing 946.

Exercise Tiger


American troops landing on Slapton Sands in England during rehearsals for the invasion of Normandy

Exercise Tiger, or Operation Tiger, was one of a series of large-scale rehearsals for the D-Day invasion of Normandy, which took place in April 1944 on Slapton Sands in Devon. Coordination and communication problems resulted in friendly fire injuries during the exercise, and an Allied convoy positioning itself for the landing was attacked by E-boats of Nazi Germany's Kriegsmarine, resulting in the deaths of at least 749 American servicemen.

Because of the impending invasion of Normandy, the incident was under the strictest secrecy at the time and was only minimally reported afterwards.

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Battle of Lyme Bay


Arrow shows Lyme Bay in south-west England

Date: 28 April 1944
Location: off Portland, England, Lyme Bay, English Channel, 50.28°N 3.64750°W
Result: German victory

Belligerents: United States, United Kingdom, Germany
US and UK strength: 1 corvette, 8 LSTs
German strength: 9 E-boats
US and UK casualties and losses: 749 killed, ~200 wounded, 2 LSTs sunk, 2 LSTs damaged
German losses: none

On the day after the first practice assaults, early on the morning of 28 April, the exercise was blighted when Convoy T-4, consisting of eight LSTs carrying vehicles and combat engineers of the 1st Engineer Special Brigade, was attacked by German E-boats in Lyme Bay. Nine German E-boats had left Cherbourg shortly after midnight, avoiding the British MTBs watching the port area and patrols in the English Channel.

Around 0130 hrs six E-boats of the 5. S-Boot Flottille (5th E-Boat Flotilla) commanded by Korvettenkapitän Bernd Klug saw eight dark ships and split into three pairs to attack with torpedoes: first Rotte 3 (S-136 & S-138), then Rotte 2 under Oberleutnant zur See Goetschke (S-140 & S-142), then Rotte 1 (S-100 & S-143). The final three E-boats of the nine, S-Boot Flottille commanded by Korvettenkapitän Götz Freiherr von Mirbach (S-130, S-145 & S-150), saw the red flares for attack (or may have heard the contact report sent at 0203 hrs) and joined the attack. After, within the Rotte 1 pair, S-100 collided with S-143 and damaged its superstructure, the boats decided to leave, masking their retreat with smoke while sending another contact report. S-145 attacked the ships with gunfire. The attack ended circa at 0330 hrs. The Germans had been puzzled by the strange-looking ships which did not look like merchantmen. They estimated that they were some type of American landing ship with a shallow draft as the initial torpedoes from Rotte 3 and Rotte 2 seemed to miss.

Of the two ships assigned to protect the convoy, only one was present. HMS Azalea, a corvette, was leading the LSTs in a straight line, a formation that later drew criticism since it presented an easy target to the E-boats. The second ship that was supposed to be present, HMS Scimitar, a World War I destroyer, had been in a collision with an LST, suffered structural damage and left the convoy to be repaired at Plymouth. Because the LSTs and British naval headquarters were operating on different frequencies, the American forces did not know this. HMS Saladin was dispatched as a replacement, but did not arrive in time to help protect the convoy.

Casualties

• LST-289 was set on fire but eventually made it back to shore with the loss of 13 Navy personnel.
• LST-507 was torpedoed and sunk with the loss of 202 US Army/US Navy personnel.
• LST-511 was damaged by friendly fire from LST-496 (intended to be directed at one of the E-boats which passed between the two LSTs) resulting in injuries to 18 US Army/Navy personnel.
• LST-531 sank within six minutes of being torpedoed with the loss of 424 Army and Navy personnel.

The remaining ships and their escort fired back and the E-boats made no more attacks. In total, 749 servicemen (551 United States Army and 198 United States Navy) were killed during Exercise Tiger. Many servicemen drowned or died of hypothermia in the cold sea while waiting to be rescued. Many had not been shown how to put on their lifebelt correctly, and placed it around their waist, the only available spot because of their large backpacks. In some cases this meant that when they jumped into the water, the weight of their combat packs flipped them upside down, dragging their heads under water and drowning them. Dale Rodman, who travelled on LST-507, commented: "The worst memory I have is setting off in the lifeboat away from the sinking ship and watching bodies float by". The 248 bodies that were recovered were sent to Brookwood Cemetery in Surrey on 29 April. The unit with the most casualties was the 1st Special Engineer Brigade.

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