Sources close to Tony-award winning actress Natasha Richardson tell FOXNews.com that the 45-year-old actress is brain dead, and being transported back to New York City before she is to be taken off life support.
Richardson's condition deteriorated following a skiing accident on Monday on a beginner's trail at the Mont Tremblant ski resort in Quebec, Canada.
A spokeswoman for Montreal's Sacré-Coeur hospital, where Richardson was transferred after being sent initially to nearby Centre Hospitalier Laurentien in Ste-Agathe, said a family representative was expected to release a statement Wednesday.
PHOTOS: Click for photos of Natasha Richardson.
Richardson, who is married to actor Liam Neeson, was reported in serious condition with a head injury by multiple outlets early Tuesday.
"We know that she has had an accident but we really do not know any more details," said Kika Markham, who is married to Richardson's uncle, Corin Redgrave. "We are very concerned."
Neeson left the set of a movie he was filming in Toronto to be by his wife's side.
"Liam Neeson left the Toronto set immediately to fly to Montreal upon news of his wife’s accident," a rep for his film said in a statement to Canadian TV. "We do not have any details at this time but we hope for the best and our thoughts and prayers are with Natasha and Liam and their family."
Neeson's reps told FOXNews.com they had "no information at this time regarding this matter."
Mont Tremblant said Richardson fell on a beginner's trail during a ski lesson and later reported not feeling well. She was not wearing a helmet, nor was one required, they said.
"She did not show any visible sign of injury, but the ski patrol followed strict procedures and brought her back to the bottom of the slope and insisted she should see a doctor," said a statement from the resort.
Mont Tremblant spokeswoman Catherine Lacasse said Richardson was getting a private lesson and that she said she was fine at first.
"An hour later she said she didn't feel well. She had a headache, so we sent her to the hospital," Lacasse said. "There were no signs of impact and no blood, nothing."
Richardson, is the daughter of actress Vanessa Redgrave and the late director Tony Richardson. She married Neeson in 1994 after they both appeared in the film "Nell." The couple have two sons.
In January, Richardson and her mother played the roles of mother and daughter in a one-night benefit concert version of "A Little Night Music," in New York.
The Associated Press contributed to this report.
Richardson at the UK premiere of ''The Chronicles of Narnia: Prince Caspian''. According to conflicting reports, British actress Natasha Richardson is brain dead following a severe head injury from a skiing accident on Monday. The New York Post reported that friends of Richardson said she "was brain dead", after earlier reporting that she was "dead". They later issued a correction which said she was brain dead. Other media reports say that her brain is severely swollen. Fox News Channel also reports Richardson as brain dead.

Richardson was transported by plane from Sacré-Coeur Hospital in Montreal, Canada to a care facility in New York City in the United States. She remains in very critical condition and reports say she is not likely to survive. Once in the U.S., she will be taken off life support.

Richardson, 45, was taking a private skiing lesson in Mont-Tremblant in Quebec when reports say she fell, hitting her head. Despite the fall, witnesses say she did not appear to have been seriously injured. An hour after the fall and after she returned to her hotel room, Richardson began to feel ill and was taken to a local hospital. She was later transported to Sacré-Coeur Hospital.

"She was talking and making jokes and there was no sign of any apparent injury. She said she was okay and didn't want to go to hospital or see a doctor. About an hour later she said she was not feeling that good after all. She said she had a headache. They agreed to dial 911 and an ambulance came to take her away," Mont-Tremblant resort ski station spokeswoman Catherine Lacasse to The Daily Telegraph.

Richardson's husband, actor Liam Neeson, has left Toronto where he was filming a movie and will be with Natasha when she arrives in the U.S.. He was acting in the movie 'Chloe', which was being filmed in the area. Both were staying at the resort in Mont-Tremblant. The couple have two children who were also staying with them, Daniel Jack age 12 and Micheal Richard Antonio age 13. They are said to have been skiing with their mother when she fell.

"Liam Neeson left the Toronto set immediately to fly to Montreal upon news of his wife’s accident. We do not have any details at this time, but we hope for the best and our thoughts and prayers are with Natasha and Liam and their family," said spokespeople for Neeson in a statement to the press. Richardson's family and spokespeople are expected to issue a statement sometime after she arrives in New York City.