On April 28, 1944, ~750 men of the US Navy and US Army are killed during the disaster of Exercise Tiger. Also known as Operation Tiger, Exercise Tiger was intended as a practice run for the Operation Overlord landings at Normandy. The plan was for Convoy T-4, consisting of eight LSTs (Landing Ship, Tank) and two escort ships, to practice an amphibious landing at Slapton Sands, Devon, England. However, only one escort ship, the corvette HMS Azalea, was present as the other escort ship, the World War I-era destroyer HMS Scimitar, had been withdrawn for repairs following an earlier collision with an LST. Also, the arrival of a replacement escort, the HMS Saladin, was delayed due to differences in radio equipment between the British and Americans hindered reporting of the need for a new escort ship.

Early in the morning of April 28, E-boats of the German Kriegsmarine attacked the convoy. Deployed from Cherbourg, the German ships had managed to sneak by the Allied patrols of the English Channel before launching their attack. Four LSTs were hit by torpedoes and two of those ships were sunk and a total of 749 men from the US Navy and US Army had perished. Many are believed to have lost their lives due to improper use of their life-belts, having placed them around their waists due to their gear getting in the way of the proper way of wearing them higher up on the body. This resulted in these men being flipped upside down by their heavy packs and, unable to right themselves, drowned. The German E-boats, following their attack, returned to base, once more evading Allied interception.

The disaster result in rapid changes in the US and British militaries. Radio equipment was standardized to ease communication between the two powers. Better training on the use of life vests and the use of small craft to rescue men in the water was put in action for the Normandy landings. Thanks to the efforts of local Devon resident Ken Small, a Sherman tank which had been lost as part of the disaster now stands on the beach as a memorial to the men who perished.