Rashidi Wheeler, a senior safety for the Northwestern football team, died Friday after collapsing during conditioning drills. He was 22.

Wheeler collapsed at about 5 p.m. and was taken to Evanston Hospital, where he died about an hour later. A team trainer administered first aid and CPR, school officials said, while Evanston Fire Department paramedics were called to the field hockey field north of Ryan Field, where the players were practicing.

“As a parent and someone who loves his own children a great deal this is the hardest thing I’ve had to do in my life,” NU coach Randy Walker said at a press conference. “We have each other and we have a lot of love and caring on this team. As I told them, I need them now more than I’ve ever needed anything in my life.”

Wheeler’s death came two days after the deaths of a high school player in Indiana and Minnesota Viking’s tackle Korey Stringer. Stringer died early Wednesday morning of heat stroke after a Tuesday afternoon practice in Mankato, Minn.

Heat is not believed to be the cause of Wheeler’s death. The temperature in Evanston was 82 degrees late Friday afternoon. NU trainer Tory Aggeler said Wheeler had a history of asthma and used his inhaler both during practice and as he was leaving the field.

The official cause of death won’t be known until after an autopsy is conducted Saturday.

Wheeler started all 12 games during last season’s Big Ten championship season, in which he recorded 88 tackles. The senior from Ontario, Calif., was a sociology major.