The boxer was out of town at the time of the incident, but has returned to be with his daughter.
Police: Tyson's daughter hurt (ESPN)
Police Sgt. Andy Hill said the "tragic accident" happened Monday morning at Tyson's home when the girl's 7-year-old brother found her on a treadmill with her neck on a cable attached to the exercise machine.
The boy told the girl's mother from another room. She took the girl off the cable, called 911 and tried to revive her."Apparently she and her older brother were watching TV in the TV room," Hill told KTAR radio station. "There was also a number of pieces of exercise equipment, and somehow the little girl got herself on a piece of equipment and she ended up kind of choking herself.
Police: Mike Tyson's daughter on life support (AP)
Mike Tyson's young daughter critical after bizarre accident (KNXV-TV)