On Nov. 17, 1991, the Detroit Lions were playing the Los Angeles Rams in what should have been a typical regular season NFL game.
But a routine pass play turned into a disaster. Lions offensive right guard Mike Utley tried to throw a block.
"My opponent went to raise his hands and then all of a sudden, right then and there, [I] went to take his legs out and that was it," Utley said. "He pulled me down and it broke my neck."
As he was carted off the field, he gave a thumbs-up sign. But Utley would never play football -- or walk -- again.
Even before his spinal cord injury, the 280-pound Utley had his share of battlefield wounds -- a shattered leg his rookie year, and two fractured ribs and a dislocated shoulder the next season.
In professional football, such a medical chart is the norm. In many cases, not even extreme fans are aware of how physically destructive the sport can be.
By this past midseason, 499 players were unable to play and 406 of them were out for the season.
"It takes a toll on your body, there's no question," said Mark Schlereth, an ex-football player. "It's like getting in a car wreck every day."
In his 12-year-career, Schlereth, an offensive lineman with the Denver Broncos, was operated on 29 times -- 15 times on his left knee, five on his right knee, six on his elbows and once on his back.
"There's nobody that plays this game that doesn't suffer some type of consequences -- from arthritic hands and joints, knuckles and broken fingers to back pain, to hip pain to neck pain, to elbows, knees, you name it," he said. "It takes a toll."
Some medical experts are alarmed by the wear and tear football players face. Some players have had as many as 10 concussions, which have been linked to cognitive memory loss.
"We have seen that 61 percent of all players in our database have reported at least one concussion during their professional playing career," said Dr. Kevin Guskiewicz of the University of North Carolina Center for the Study of Retired Athletes.
It's easy for people to rationalize the injuries football players sustain because they think the athletes are so well-paid.
But many players do not collect disability benefits. The requirements to qualify are stringent and only 130 out of 7,500 former players are collecting disability payments today.
In addition, aside from the stars, most football players make far less than the famous players like quarterbacks Peyton Manning and Tom Brady -- and many do not have guaranteed contracts. The average football career is 3.5 to 4 years and when it ends, the money is gone.
But players like Schlereth and Utley say their love of the game sustains the battle-weary players.
"That's the price you pay," Schlereth said. "You understand that going in. You understand that you got to pay that price ultimately."
Today, if he could, Utley said he would be back on the field today.
"If, God willing, if I could come back and play again at 40 years old, I'd try out again," he said. "If somebody would give me an opportunity, I'd go out and try again. My God, I'd go out and do it."