Hundreds of cyclists are making their way from Boston to New York City to honor firefighters who were killed in the Sept. 11 terror attacks.

Livestrong's First Responder Ride for Resilience started outside Fenway Park on Sunday.

It's a five-day, 343-mile ride to New York - one mile for every firefighter who died in the attacks.

The ride also honors those who are battling long-term effects of 9/11-related illness.

Over 200 riders, including first responders and cancer survivors, are participating.

The ride raises money for organizations, including Livestrong and Friends of Firefighters.