Actress Natasha Richardson, who died yesterday after a seemingly minor fall on a Canadian ski slope, was killed by blunt trauma to her head, a coroner said today.

Richardson, 45, died of an epidural hematoma, a bleed between the skull and the dura, the lining that covers the brain, New York's medical examiner ruled. Richardson was flown to New York, where she and her husband Liam Neeson, 56, have a home, after Monday's fall. Her death was ruled an accident.

“It can bleed profoundly, causing a clot that expands between the skull and the dura, and you get pressure on the brain,” David Langer, director of cerebrovascular neurosurgery at St. Luke's-Roosevelt Hospital in Manhattan, told the New York Times. “It can be quite dramatic. It’s one of the most acute neurological emergencies. It’s one of the few times where it’s life or death, where you can truly save somebody’s life, or they die if you don’t get to them.”

Richardson was walking and talking after she fell, but developed a pounding headache soon afterwards. Our Ask the Experts Q&A on talk-and-die syndrome explains more about this mystifying phenomenon.

Image of human brain © iStockphoto/Vasiliy Yakobchuk