PHOENIX — The near-fatal strangulation of boxer Mike Tyson's 4-year-old daughter appears to be a "tragic accident," police say.

Exodus Tyson was on life support Tuesday after apparently accidentally hanging herself on a cord dangling from a treadmill in her modest central Phoenix home.

"Somehow she was playing on this treadmill, and there's a cord that hangs under the console — it's kind of a loop," police Sgt. Andy 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."

Exodus' 7-year-old brother found her Monday and told their mother, who was in another room. She took Exodus off the cord, called 911 and tried to revive her.

Responding officers and firefighters performed CPR on Exodus as they rushed her to a nearby hospital, where she was in "extremely critical condition" and on life support, Hill said.

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," adding 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."

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."