The story of Pat Tillman has been told frequently since the 27-year old NFL player was killed in Afghanistan after enlisting in the U.S. Army in the aftermath of the 9/11 terrorist attacks. Many of the stories about Tillman make a passing reference to Bob Kalsu of the Buffalo Bills without detailing the story of the only active pro football player to die in combat in Vietnam.

Kalsu’s story was made more tragic by the birth of his son just days after his death.

Pat Tillman’s tragedy reminded us that athletes could serve, too

With the days of the draft and mandatory military service behind us, Pat Tillman was a rarity: a successful pro athlete who wore a different kind of uniform. Making his situation more unusual, Tillman signed on for military duty after having already established himself as an NFL player.

Tillman and his brother Kevin enlisted in Army Ranger School in the aftermath of the Sept. 11, 2001, terrorist attacks. He was walking away from a career that had begun with 39 starts at cornerback over four seasons for the Arizona Cardinals after being drafted in the seventh round in 1998.

The Army revealed Tillman’s death on April 22, 2004, and the circumstances remain a source of controversy. At his funeral, a Navy SEAL described how Tillman died providing cover for fellow soldiers, but Tillman’s family was told a month later that it was a case of being struck down by friendly fire. Hearings three years later confirmed his death came from friendly fire and that the military may have intentionally misled the family.

Who was Bob Kalsu, the Buffalo Bills player who died in Vietnam?

While his Buffalo Bills teammates were preparing for the 1969 American Football League season, offensive lineman Bob Kalsu was in training with the 101st Screaming Eagles Airborne Division that was preparing to ship out to Vietnam.

His circumstances were a reminder of a different era for young men in the United States. While some athletes were able to defer their military service or fulfill their obligation via the National Guard, Kalsu was a member of the ROTC program at the University of Oklahoma and commissioned as a second lieutenant. When the members of his unit were called up, Kalsu opted to join them.

Kalsu had landed with the Bills in 1968 as an eighth-round draft pick after a stellar career with the Sooners that included being selected an All-American at offensive tackle. He added 30 pounds following her senior season, moved to guard, and finished an otherwise dismal season – the Bills went 1-12-1 in the AFL East – by being selected the team’s rookie of the year.

Bob Kalsu died in the line of duty in Vietnam

Buffalo Bills player Bob Kalsu shipped out to Vietnam late in 1969, leaving his infant daughter and his pregnant wife behind. By the early in the following summer, he found himself promoted to first lieutenant in one of the most hellish battlefields of the war.

The 101st Airborne Division was assigned to Fire Base Ripcord, an elevated slice of land from which two artillery batteries provided support to two battalions of infantry in the jungles. As recounted in Sports Illustrated in 2014, those batteries had created havoc for the enemy by pounding supply lines and had become a strategic target.

On July 17, four days before his wife was due to give birth and in the face of an intensifying insurgence by 10 to 12 battalions of enemy combatants, Kalsu became the acting commander of a battery unit after his captain was wounded. Shelling from the North Vietnamese was becoming more persistent and grew worse each time U.S. helicopters landed to resupply Fire Base Ripcord.

Rather than riding out the worst of it in the bunker, Kalsu exposed himself to the same danger his soldiers faced while unloading 97-pound explosive rounds. During a lull on July 21, Kalsu was with a friend from the unit just outside the bunker and reading a letter from his wife about the impending birth of their son.

Suddenly, an enemy mortar round crashed onto Fire Base Ripcord five feet at the bunker door. The force of the explosion blew Kalsu and another soldier through the door and six feet down into the bunker, which partially collapsed.  

Tribute to a fallen hero

The attack on July 21, 1970, killed Buffalo Bills lineman Bob Kalsu at the age of 25. Jan Kalsu would give birth to a son less than 48 hours later, not yet knowing that her husband had died in action in Vietnam.

In 1990, the Bills unveiled a memorial at Rich Stadium to honor Kalsu, the only active pro football player killed in the Vietnam War. The honor would be followed a decade later by the addition of Kalsu’s name to the stadium’s Wall of Fame.

The Pro Football Hall of Fame in Canton, Ohio, also has a display honoring Kalsu’s memory.