The NYC medical examiner's office says Natasha Richardson died of blunt impact to the head.
A spokeswoman for the ME says the death has been ruled an accident. The cause of death is "epidural hematoma due to blunt impact to the head."
Dr. Wouter Schievink, a neurosurgeon at Cedars-Sinai Medical Center in Los Angeles, tells TMZ a common example of someone suffering an epidural hematoma is when a baseball player is hit on the side of the head by a pitch.
He also says that an epidural hematoma can be detected by a CT scan. But sometimes if the scan is performed early on, the injury might not be detected.