NEW YORK - Liam Neeson looked distraught but grateful for the outpouring of sympathy as he greeted grieving family members and friends who attended a private viewing for wife Natasha Richardson on Friday.

Neeson was the last to leave the viewing at the Upper East Side's American Irish Historical Society, where he was joined by the couple's sons, -- Micheal, 13, and Daniel, 12 -- as well as Richardson's mother, Vanessa Redgrave, and sister, Joely Richardson. An array of famous friends came to express their sadness about the family's sudden loss.

Neeson hugged friends as he left the society's building at 8:40 p.m., after more than six hours of receiving condolences from friends including Mike Nichols, Diane Sawyer, Matthew Modine, Ralph Fiennes, Uma Thurman, Ethan Hawke, and Sarah Jessica Parker.

Also among the stream of visitors were Kenneth Cole, Laura Linney, Fisher Stevens, Howard Stern, Stanley Tucci, Julianna Margulies and Mathilde Krim of the American Foundation of AIDS Research. Richardson had served on the charity's board of trustees since 2006.

"She looked incredibly beautiful," Krim said, adding that everyone appeared to be in shock and Neeson looked distraught as he received everybody.

Earlier Friday, friends continued to express their grief over her death from the fall she took on a ski slope.

"Natasha was a very close friend of our family, so it's been a very, very sad few days, and I think it will stay that way for a good while," Matthew Broderick said.

Actor Jonathan Cake said: "I had dinner with her Saturday night. ... She left to ski the next day."

Theatres in London's West End dimmed their lights Friday to mark Richardson's death, just as Broadway theatres did Thursday. In a tribute to the stage and screen actress, the lights were lowered before the curtains went up on evening performances.

Richardson, 45, died Wednesday at Lenox Hill Hospital after falling at the Mont Tremblant resort in Quebec on Monday. The New York City medical examiner's office ruled her death was an accident.

Nearly four hours elapsed between her fall and her admission to a hospital. The director of operations at the emergency services company that sent paramedics to the resort said the actress initially declined medical attention, but a second 911 call was made more than two hours later. Medics returned and tended her for a half-hour before transporting her to a hospital a 40-minute drive away.

Montreal's top head trauma doctor said Friday that the lack of medical helicopters in the province of Quebec may have played a role in Richardson's death.

"It's impossible for me to comment specifically about her case, but what I could say is ... driving to Mont Tremblant from the city (Montreal) is a 2 1/2-hour trip, and the closest trauma centre is in the city. Our system isn't set up for traumas and doesn't match what's available in other Canadian cities, let alone in the States," said Tarek Razek, director of trauma services for the McGill University Health Centre, which represents six of Montreal's hospitals.

Being driven by ambulance to two separate hospitals, rather than airlifted by helicopter directly to a trauma centre, could have cost Richardson crucial moments, he said.

"A helicopter is obviously the fastest way to get from Point A to Point B," he said.

Centre Hospitalier Laurentien, the first treatment centre Richardson was brought to, does not specialize in head traumas, so her speedy transfer to Sacre Coeur Hospital in Montreal was critical, said Razek.

"It's one of the classic presentations of head injuries, `talking and dying,' where they may lose consciousness for a minute, but then feel fine," said Razek.

Razek said immediate treatment might have helped Richardson but added: "There are so many variables, it's hard to speculate what might have been done differently."