NEW YORK (WABC) -- The 15th annual Tunnel to Towers run is being held Sunday in honor of firefighter Stephen Siller, who died in the September 11 terror attacks.
The race traces the heroic steps he took when he abandoned his truck in Brooklyn and ran to the towers of the World Trade Center.
Among the 25,000 runners are about 100 from last weekend's Seaside Park Semper Fi Marine Corps fundraiser in New Jersey, which was canceled after the pipe bomb explosion.
All the money raised in Sunday's event will be for the Stephen Siller Tunnel to Towers Foundation, supporting first responders and wounded veterans of the Iraq and Afghanistan wars.
Many streets across Brooklyn and Manhattan are closed for the race.
Organizers say hundreds of security officers will be at the Manhattan race.