GRENOBLE, France (AFP) - Formula One legend Michael Schumacher was on Tuesday still in coma and fighting for his life with his family at his bedside after a skiing accident in the French Alps.
Doctors have warned it is touch-and-go for the German, the greatest champion in the history of Formula One, as they wait for the full extent of his injuries to become clear after he fell and slammed his head on a rock while skiing off-piste on Sunday.
Schumacher's wife Corinne and children Gina Maria and Mick were by his side and a small crowd held a night vigil outside the hospital in the southeastern city of Grenoble, an AFP reporter said.
A source close to the investigation into the off-piste accident at the posh ski resort of Meribel told AFP that Schumacher's helmet was smashed "in two" by the impact.
The German newspaper Bild also quoted a rescuer as saying the split helmet was "full of blood".
Schumacher's family in a statement expressed their thanks to the doctors who they said were doing "everything possible to help Michael" and to well-wishers around the world.
The family also asked the press to "respect their privacy," in the statement put out by Schumacher's spokeswoman Sabine Kehm.
News of the accident stunned the world and racing stars joined German Chancellor Angela Merkel and legions of fans in expressing their hopes for his recovery.
The hospital said it would put out a medical bulletin on Tuesday. Neurosurgeon Stephan Chabardes, who operated on Schumacher, had earlier said medical updates would be provided as and when necessary.
Doctors said a second operation was on the cards for Schumacher, who is due to turn 45 on Jan 3, and stressed it was too early to say if he would pull through.
"It usually takes 48 hours, or even longer, to be able to formulate an opinion" on injuries of this severity, said neurologist Jean-Luc Truelle.
The coma reduces the patient's temperature to around 35 deg C to reduce swelling. By being unconscious, the brain is also switched off to sounds, light and other triggers that cause the organ to use up oxygen as it processes the stimuli.
"He is in critical condition, his condition can be described as life threatening," Jean-Francois Payen, head of the intensive care unit, told reporters.
"We are working hour by hour," he said.
News of the accident made waves, stunning fans, racing stars and leaders across the world.
Damon Hill, who fought several memorable on-track battles with Schumacher, said he was "praying" for his former rival.
Dr Merkel was "extremely shocked" by the incident, her spokesman Steffen Seibert told reporters.
Formula One quadruple world champion Sebastian Vettel, 26, who has said Schumacher was his childhood idol, said: "I am shocked and I hope that he'll be feeling better as soon as possible.
Schumacher, who won the last of his world titles in 2004, towered over the sport since his debut in 1991, winning more Formula One world titles and races than any other. He had a record 91 wins and is one of only two men to reach 300 grands prix.
His duels in his heyday with Hill and Jacques Villeneuve, fired by an unquenchable competitive spirit, have gone down in Formula One lore.
Schumacher was born in January 1969 near Cologne, Germany, the son of a bricklayer who also ran the local go-kart track, where his mother worked in the canteen.
By 1987, Schumacher was the German and European go-kart champion and was soon racing professionally. In 1991 he burst into Formula One by qualifying seventh in his debut race in Belgium and a year later, he won his first Formula One grand prix.
He joined Ferrari in 1996 and went from strength to strength over the next decade, dominating the podium, before retiring aged 37.
But the father of two could not resist the lure of the track and in 2010 he came out of retirement, signing a deal with Mercedes before quitting for good in 2012.