updated 03/19/2009 AT 2:00 PM ET
•originally published 03/19/2009 AT 2:30 PM ET
Actress Natasha Richardson died from a blunt impact to the head, a spokesperson for the New York City medical examiner’s office tells PEOPLE. Her death was ruled an accident Thursday after an autopsy was performed.
The blunt impact caused internal brain bleeding, which is what killed her, the M.E.’s office reports, but it is still unknown exactly how she injured her head.
Richardson’s nightmare began Monday afternoon during a private ski lesson on a beginner hill at Mont Tremblant in Quebec. Mont Tremblant rep, Catherine Lacasse, says Richardson fell and tumbled during her private ski lesson. She fell in the middle of the ski run and did not appear to hit any object aside from the snow on the ground.
Lacasse also told PEOPLE that 45-year-old Richardson initially appeared fine and was “lucid, talking, even making jokes.”
Two ski patrol officers and her ski instructor tended to her at the scene where she initially declined to go to the hospital, said the rep. Instead, the trio accompanied her back to her hotel room. About an hour later, “she started to suffer headaches and the instructor said, ‘Okay, you better go to the hospital,’ and she agreed,” said Lacasse.
An ambulance took her to a nearby hospital, Centre Hospitalier Laurentien, and later in the day she was taken to Sacre Coeur Hospital in Montreal, where was treated in the intensive care unit.
The Greenwich Village Funeral Home is handling her arrangements.