Rock star Ozzy Osbourne stopped breathing and his heart stopped beating after his quad bike accident on Monday, his wife Sharon has told a newspaper.
Sharon Osbourne flew from Los Angeles to be with her husband
"He had stopped breathing for a minute and a half and there was no pulse," she told the Daily Mirror.
"But thank God, the security guard was there to revive him," she said.
Doctors at the Berkshire hospital where Osbourne is being treated say he is being weaned off a ventilator and is "progressing well, but slowly".
"With each day he becomes less dependent on the ventilator," the hospital's medical director, Dr Dick Jack, said.
But "it is still too early to take him off entirely," he said.
Meanwhile, Pop Idol judge Simon Cowell has apologised for joking on BBC Radio Five Live that Osbourne's accident may have been a stunt to boost record sales.
"Some people may even say he fell off on purpose," Cowell told DJ Simon Mayo on Tuesday. "It is going to help his record sales."
His comments provoked a furious response from Sharon Osbourne.
"If I could tar and feather him and handcuff him to lamppost in Piccadilly, I would do it this instant," she told the Mirror.
Cowell later recanted his remarks. "I had no idea that Ozzy was seriously ill. I apologise unreservedly and wish Ozzy a speedy recovery," he told the tabloid's reporter.
The singer and TV star fractured eight ribs and a vertebra in his neck in the accident.
Sharon Osbourne told the newspaper her husband "stopped breathing and the guard spotted it immediately".
"He resuscitated him and got him breathing and his pulse
going again. We are so, so grateful to him," she said.
Ozzy Osbourne had emergency surgery after the crash to restore the flow to a damaged blood vessel.
His wife said the crash happened as he drove over uneven ground, and the bike landed on top of him.
"The doctors are hoping there hasn't been any lasting damage, but until Ozzy can actually come round and get off the ventilator and then they will know," she said.
On Thursday, the couple's daughter, Kelly, said her father was awake and feeling better because he had moaned about the nurses.
"He gave me the thumbs-up and stuck his tongue out at me," she said.
Osbourne, singer with heavy metal band Black Sabbath, has enjoyed renewed success in recent years because of the MTV reality show based around his family life in Los Angeles.