State troopers say a New York City philanthropist was critically injured Friday when her car slammed into the rear of a tractor-trailer in Katonah.

Troopers say a station wagon driven by 80-year-old Eleanor Elliott sped up on a ramp from Interstate 684 and rear-ended a tractor-trailer. Police say the car then rolled back down the ramp a short way and ended up against a guardrail. The accident closed the ramp to Route 35 for several hours. State troopers also diverted cars from the Saw Mill Parkway, which merges with 684. Police say they do not know what caused the accident, but they do know it was not caused by weather.

Elliott is described as a philanthropist from New York City, who also has a house in Cross River. She graduated from Barnard College and has a residence hall named after her. Elliott also wrote for Glamour Magazine and has been active in several charitable organizations. She was taken by ambulance to the Westchester Medical Center in Valhalla and is listed in critical condition.