The events of D-Day on June 6, 1944, were the result of years of careful planning, deception, good luck, and setbacks. As we near another D-Day anniversary, it is important to understand what transpired before the massive invasion of Normandy. Here are a few highlights that you may have never heard about:

The Tragedy and Massacre at Slapton Sands

In April 1944, in Slapton Sands, Devon, Allied troops conducted a large-scale mock invasion to prepare for the inevitable invasion of Normandy. The training operation was dubbed Exercise Tiger and involved over 30,000 men.

On April 27, a large Allied beach landing was planned. General Eisenhower had ordered British battleships to shell the beach with live rounds, right up until the landing craft landed, in an attempt to prepare soldiers for what they would encounter in Normandy. At the last minute, the invasion was pushed back an hour. But of course, not all of the invasion units learned of this schedule change, resulting in some Higgins boats landing on the beach early and being hit by friendly fire.