Updated

Mike Tyson's 4-year-old daughter is on life support and in "extremely critical condition" after she was discovered hanging from a treadmill cable in her family's Phoenix home, police said.

Exodus Tyson's 7-year-old brother found her Monday with her neck in a cord dangling from the exercise machine, police Sgt. Andy Hill said, calling it a "tragic accident."

The mother sent the boy to find his little sister, who was playing in a separate room. That's when he saw her in distress and got his mother, police said.

"Somehow she was playing on this treadmill, and there's a cord that hangs under the console — it's kind of a loop," Hill said. "Either she slipped or put her head in the loop, but it acted like a noose, and she was obviously unable to get herself off of it."

The girl's mother took her daughter out of the cable, called 911 and attempted to revive her.

Responding officers and firefighters performed CPR on the little girl. She was rushed to nearby St. Joe's Hospital after she was found around 10:30 a.m. local time, MyFOXPhoenix.com reported.

Hill said former heavyweight champion Tyson, 42, had been in Las Vegas but flew to Phoenix immediately after learning of the accident.

"The Tyson family would like to extend our deepest and most heartfelt thanks for all your prayers and support, and we ask that we be allowed our privacy at this difficult time," the boxer said in a statement.

Brief footage from local TV station KTVK showed Tyson arriving at the hospital in a white button-up and black pants, and looking around with a frown before going inside.

Hill said everything in the investigation pointed to a "tragic accident."

"There's nothing in the investigation that revealed anything suspicious," he said.

He added that calls involving children is an officer's most difficult duty.

"Those are the things that stay with you in your career," he said. "We always hope for a miracle — not to have the worst happen to a child."

Tyson lives in the house with his girlfriend and their two children, MyFOXPhoenix.com reported.

Neighbors said they were surprised and saddened when they heard what had happened.

"It's terrible," said Abby St. Jermain, who grew up in the neighborhood and is house-sitting for her parents down the street. "The kids are so sweet. We always see them riding their bikes, playing. They've just been wonderful people."

Dinka Radic, who lives across the street, described Exodus as smart and sweet.

"The little girl, she says 'You got chocolate in your house?"' Radic said. "I say 'Yes,' and she says, 'OK, give me some."'

When she gives the girl the chocolate, Radic said "she just kisses me on my knees. Kiss, kiss, kiss. Very nice."

Click here to read more on this story from MyFOXPhoenix.com.

The Associated Press contributed to this report.