It was the invasion to save civilization, and LIFE’s Robert Capa was there, the only still photographer to wade with the 34,250 troops onto Omaha Beach during the D-Day landing.

His photographs—infused with jarring movement from the center of that brutal assault—gave the public an American soldier’s view of the dangers of war.

The soldier, in this case, was Private First Class Huston Riley, who after the Nazis shelled his landing craft jumped into water so deep that he had to walk along the bottom until he could hold his breath no more.

When he activated his Navy M-26 belt life preservers and floated to the surface, Riley became a target for the guns and artillery shells mowing down his comrades. Struck several times, the 22-year-old soldier took about half an hour to reach the Normandy shore.

Capa took this photo of him in the surf and then with the assistance of a sergeant helped Riley, who later recalled thinking, “What the hell is this guy doing here? I can’t believe it. Here’s a cameraman on the shore.” Capa spent an hour and a half under fire as men around him died.

A courier then transported his four rolls of film to LIFE’s London offices, and the magazine’s general manager stopped the presses to get them into the June 19 issue.

Most of the film, though, showed no images after processing, and only some frames survived. The remaining images have a grainy, blurry look that gives them the frenetic feel of action, a quality that has come to define our collective memory of that epic clash.