The Devon D-Day practice which ended in disaster in South Devon

Today is the 80th anniversary of D-Day, the largest amphibious invasion in military history that decisively shifted the course of the Second World War.

The invasion commenced with a 1,200-plane airborne assault followed by a massive sea assault involving over 5,000 vessels landing on Normandy, France. On June 6, 1944, nearly 160,000 troops crossed the English Channel, and by the end of August, more than two million Allied troops were in France.

Two months before D-Day, a training exercise in Devon ended in tragedy, claiming nearly 800 lives. Troops rehearsing for the invasion at Slapton Sands, South Devon, fell victim to one of Devon's most tragic events. The specifics remain unclear, but in the days following April 28, 1944, hundreds of American servicemen's bodies washed up along the Lyme Bay coastline.

The disaster occurred during Exercise Tiger, a week-long mock invasion. Initially, plans were going smoothly. The previous year, 3,000 residents around Slapton were given six weeks to evacuate their homes. In spring 1944, thousands of American soldiers arrived, poised to lead the D-Day assault.

Shrouded in secrecy, the operation included a dress rehearsal at Slapton, chosen for its resemblance to Utah Beach. The exercise became a catastrophe and remained a secret for three decades. On the night of the attack, German torpedo boats intercepted Allied radio traffic and spotted eight vessels in Lyme Bay.

Despite detection by the Royal Navy corvette HMS Azalea, a typographical error in the orders meant that the Americans and British Navy HQ operated on different radio frequencies, missing the warning of the impending danger. The German E-boats attacked, sinking two landing crafts loaded with gasoline and explosives, killing hundreds.

Misfortune plagued the exercise. A landing craft rammed one of the guardships, and a replacement arrived too late. German E-boats detected by a destroyer off Portland Bill were relayed to Plymouth headquarters, but due to a radio mishap, the convoy never received the warning. The casualties from Exercise Tiger exceeded those on Utah Beach during D-Day.

In the chaos, commanders ordered remaining vessels to scatter, leaving many soldiers to die from hypothermia in the freezing sea. Laden with soaked clothing and gear, many men drowned. Improperly fastened life jackets caused some to roll over, submerging their faces in water.

Survivors recounted the horrific scene. One survivor said, "You could walk to the beach on the floating bodies." Those who reached shore faced another calamity, still unrecognized by the Pentagon. They claimed to encounter shell fire from HMS Hawkins and "friendly fire" from beach gun positions. About 300 men are believed to have died from friendly fire, though these claims remain unverified.

Steven Sadlon, a former radio man from New York, vividly recalled the scene: "There were flames everywhere and the poor guys were screaming to death." He lost consciousness after over five hours in the water and was saved by LST-515, whose captain, John Doyle, defied orders to rescue survivors. Sadlon, covered in 14 blankets, was told he was a lucky man.

William Hicks, a ship fitter from Michigan, survived ten hours in the water after LST 507 sank. "I was blown into the water for ten hours before a British destroyer picked me up," he recounted.

Exercise Tiger's official death toll of 749 exceeded that of Utah Beach on D-Day, marking the greatest loss of American troops since Pearl Harbor. Initially, the events at Slapton Sands were withheld, but whispers spread with the arrival of coffins in Devon. The deceased soldiers were buried in the American cemetery or sent home to their families.