BROOKLYN - The 15th annual Tunnel to Towers run kicked off at the Brooklyn-Battery Tunnel Sunday morning.

The event was in honor of fallen firefighter Stephen Siller, who died in the Sept. 11 terror attacks.

Siller was last seen leaving his truck in Brooklyn to run through the Brooklyn-Battery Tunnel to the World Trade Center.

Each year, tens of thousands of runners retrace the steps Siller took in his selfless act to save others.

The Stephen Siller Tunnel to Towers Foundation has raised more than $70 million over the years.

Funds go toward building homes for injured first responders and wounded veterans of the Iraq and Afghanistan wars.