On the day before the greater armed invasion in history, 2nd Lt. Frank J. Kuhn Jr., then 26 years old, was afraid that his legs were going to get wet.

As Allied forces readied nearly 5,000 ships and 200,000 troops to invade Europe on June 6, 1944, Kuhn, sitting alone in a cold steel corner of a tank landing craft that bobbed in the English Channel, took off his pants.

He stripped plastic rifle waterproofing from two M-1 carbines, put the plastic sheaths on his legs and pulled on his pants. The next day - D-Day, about one hour before he ran onto the Normandy beach - Kuhn began to worry that he would look like an idiot if a German shot him in the legs. He would have explain his plastic underwear to the medics.

"Fear acts in strange ways," Kuhn said yesterday, sitting in his Mount Vernon area home, awash in memories of a day 35 years ago when 1,465 Americans died. He remembered that he did not have time to shed the plastic.

Kuhn now 61, a retired major from the Army Crops of Engineers and a retired insurance salesman, was one of the first American soldiers to crawl that day on the French coastline - in the sand of an invasion beach the Allies had named Utah.

In a 24-hour period when military historians estimate that the Allied troops of the United States, Britain, Canada and France suffered nearly 10,000 casualties and German losses were estimated at nearly 9,000, Utah Beach was not a bad place invade.

The 4th Infantry Division, which stormed Utah Beach, suffered only 200 casulties. Part of the reason for the Allied success was a mistake - the assault craft that landed at Utah went ashore about a mile from their designated objective. The mistake put them our of reach of many German guns.

At least one landing craft, however, came ashore at Utah Beach where it was supposed to land. Frank Kuhn, who was aboard that craft, found himself and his 26 men curiously without company.

Kuhn, who was leading a squad of "demolition experts," had orders to clear lethal-looking steel and concrete obstacles, along with land mines, from a 50-yard swath of beach.

The landing craft that brought Kuhn and his men to Utah flopped its steel door down on dry sand at about 6 a.m., 30 minutes before the official H-Hour of the invasion. Kuhn ran out of the craft without getting his feet wet. The plastic leggings, he remembers, were awfully sweaty.

Part of the first invasion wave was due in about a half hour to march through the swath Kuhn's men had been ordered to clear. Kuhn's unit began blowing up beach obstacles, challenged only by sporadic small-arms fire from the Germans.

When the work was nearly done, Kuhn said he looked southward along the beach and saw that the invasion was about to happen in the wrong place.

"We didn't know what to do," Kuhn said, "so I told the men to follow me and we walked along the beach to where the soldiers were running ashore."

On the way, a mortar shell exploded near Kuhn and knocked him on his back. "I thought I was hit. I couldn't get my breath," Kuhn recalls. Mortar fragments had hit Kuhn's binoculars, which he wore on a strap and which protected the middle of his chest. Kuhn's mother, now 89 and living in Philadelphia, still has the mangled binoculars.

Enemy fire on Utah beach generally was light and ill-aimed. Historians say the Germans there were confused by paratroops of the 82nd and 10st Airborne who had landed in the moonlit early morning hours. Kuhn's men suffered only one casualty - a sergeant was hit in the leg by fire from an Allied ship in the Channel.

The story on the other invasion beaches, especially Omaha, was far bloodier. On Omaha, hundreds of American were killed by German machine gun fire from cliffs and high bluffs. There, as at Utah beach, troops stormed the wrong places. But at Omaha the mistakes were costly.

Small boats were launched in rough seas too far from the beach. Twenty-seven tanks and crews sank. Landing craft were swamped. Soldiers, some carrying as much as 250 pounds of equipment, drowned in the surf. Later waves of troops had to slog through surf and sand that was clogged with bodies.

At Utah, the American forces were surprised at first by their good fortune. But Brig. Gen. Theodore Roosevelt - the eldest son of President Theodore Roosevelt and a bully character much like his father - decided to take advantage of the mistaken landing. He ordered the entire 4th Division to land there.

While Roosevelt was on the beach, Kuhn remembers that he walked up to the general and saluted. "I was young in those days and I didn't know what I was doing. I walked over to this man with a star on his shoulder, who was carrying a walking stick and I said I was 2nd Lt. Kuhn.

"The general said, 'So what, So what. So what,'" Kuhn recalls. Roosevelt died of a heart attack 36 days after invasion. He received the medal of Honor for leading the first wave ashore and establishing them inland.

In the campaign across Europe that followed D-Day, Kuhn helped build and destroy bridges. He served with occupation forces in Leipzig, Germany, after the war. He retired from the Army in 1958.

As to his fear of dying on D-Day, Kuhn said he kept hoping in the landing craft on the night before the invasion that somehow there would be an armistice. "I was concerned that, since we didn't have any radios, there could be an armistice and we'd go on this invasion without knowing." CAPTION: Pictures 1, 2 and 3, A faded photograph of himself in 1944, upper left, is among Frank J. Kuhn's memoirs of World War II and the D-Day invasion landing on Utah Beach, center. At right, Kuhn as he appears today. By Larry Morris - The Washington Post; Map, no captian, The Washington Post