Teddy Einstein was struck and killed by a car while riding his bicycle in Delaware County, Pennsylvania, on December 3, 2025. Teddy was a beloved husband to Ruth Fahey and father to six year old Charlie and two year old Lorcan Einstein. He was a brilliant mathematician who earned his PhD from Cornell University and taught at the University of Illinois, the University of Pittsburgh, and Swarthmore College. He loved brewing beer, cooking, and hosting parties. Friends remember his warmth, his wit, and his generosity. He was passionate about bicycling and worked to make the Philadelphia area safer for cyclists. Most of all, Teddy was dedicated to his family.

An experienced cyclist, Teddy and his wife Ruth were Philly Bike Action members living in West Philly. Bikes were one of the main ways they moved their family around. Although they practiced safe biking habits, there will never be a helmet strong enough nor clothing bright enough to make-up for dangerous infrastructure.

This page is seeking to raise money to support Teddy's surviving family as they fight for justice in his memory. All funds will go directly to Ruth who will use them to protect Teddy's legacy and enact real change to prevent this tragedy from happening to anyone else.

Ruth, Charlie, and Lorcan are seeking your care and companionship during this difficult time. Please support the family any way you can.