Bill Nack's fine 2001 SI story:

The feeling had gone out of everything. It was like we were zombies. You didn't care anymore. July was terrible. The [North Vietnamese] whacked Ripcord, that hill we were on, with mortars and rocket fire. Day after day, night after night. I was getting shell-shocked. I didn't care if I got out. At night you could hear the [enemy] yelling from the jungles all around, "GI die tonight! GI die tonight!" This was our deathbed. We thought we were going to be overrun.
—SPC. 4TH CLASS DANIEL THOMPSON, wireman at Firebase Ripcord, Vietnam, July 1970

There were always lulls between the salvos of incoming mortars, moments of perishable relief. The last salvo had just ended, and the dust was still settling over Firebase Ripcord. In one command bunker, down where the reek of combat hung like whorehouse curtains, Lieut. Bob Kalsu and Pfc. Nick Fotias sat basting in the jungle heat. In that last salvo the North Vietnamese Army (NVA), as usual, had thrown in a round of tear gas, and the stinging gas and the smoke of burning cordite had curled into the bunkers, making them all but unbearable to breathe in. It was so sweltering inside that many soldiers suffered the gas rather than gasp in their hot, stinking rubber masks. So, seeking relief, Kalsu and Fotias swam for the light, heading out the door of the bunker, the threat of mortars be damned. "Call us foolish or brave, we'd come out to get a breath of fresh air," Fotias recalls.

It was Tuesday afternoon, July 21, 970, a day Kalsu had been eagerly awaiting. Back home in Oklahoma City, his wife, Jan, was due to have their second child that very day. (They already had a 20-month-old daughter, Jill Anne.) The Oklahoma City gentry viewed the Kalsus as perfectly matched links on the cuff of the town. Jan was the pretty brunette with the quick laugh, the daughter of a successful surgeon. Bob was the handsome, gregarious athletic hero with the piano-keys grin, the grandson of Czech immigrants for whom America had been the promised land and Bob the promise fulfilled. As a college senior, in the fall of 1967, the 6'3", 220-pound Kalsu had been an All-America tackle for Oklahoma, a team of over-achievers that went 10-1, beating Tennessee in the Orange Bowl. The next season, after bulking up to 250 pounds, Kalsu had worked his way into the starting offensive line of the Buffalo Bills, and at season's end he had been named the Bills' rookie of the year.

While in Vietnam, Kalsu rarely talked about his gridiron adventures. Word had gotten around the firebase that he had played for the Bills, but he would shrug off any mention of it. "Yeah, I play football," he would say. What he talked about—incessantly—was his young family back home. Jan knew her husband was somewhere "on a mountaintop" in Vietnam, but she had no idea what he had been through.