Kyle Calloway died at the age of 29 this weekend. Getty Images

Former Bills draft pick Kyle Calloway was killed over the weekend after being struck by a train in Arizona.

According to police in Tucson, Calloway died on Saturday after "he was struck from behind by a westbound train." Authorities noted that he had been jogging "on and off the tracks."

Calloway's father, Ed, told the Cedar Rapids Gazette that running near the tracks was something that his son enjoyed.

"That was what he did for exercise," Ed Calloway said. "He liked to run and it had rained the day before and the area where he ran was muddy, and so he was going back and forth across the tracks to get out of the mud."

Ed Calloway also added that it's possible that his son may have been confused about which way oncoming trains would be traveling.

"The longer version is at our old house, the train on the right side of the tracks went east, and the train on the left tracks went west," Ed Calloway said. "Our presumption is this train was on the opposite side that he was used to so he got on to the side so the train would have been coming at him from the front. We think that he got confused because the train somehow had been slopped over and was going in a different direction that he was used to. We don't know, we're just assuming that's what happened."

Kyle Calloway was selected by the Bills in the seventh round of the 2010 NFL Draft. However, he only played in three preseason games with the Bills and was cut before the regular season started. The lineman also latched on with the Ravens for a short period of time in 2011, playing in two preseason games with Baltimore.

In college, Kyle Calloway was a three-year starter at Iowa, where he was named to the second-team All-Big 10 on two occasions.

Calloway was 29.

Kyle's family told The Gazette that they would be donating his brain to help with the study of CTE effects on football players.