Boxing Legend Muhammad Ali in ICU

According to a source, guests at his Scottsdale, Arizona, home called 911 in the early hours of Thursday morning.

“He wasn’t responding,” said the source. “He went to bed Tuesday night, but didn’t wake up in the afternoon or evening the next day. He was sleeping for 24 hours.”

The source close to the family added that by the time emergency services were alerted, the heavyweight champ, who suffers from Parkinson’s disease, had been asleep for well over a day.

“They thought he might be too exhausted,” continued the source.