The relatives and friends of a Park Slope firefighter remembered him with the annual Tunnel To Towers Run Sunday.

Stephen Siller was off-duty when he strapped on his gear and ran through the Brooklyn/Battery Tunnel toward the Twin Towers to assist in the Sept. 11 attacks because he couldn't drive through the tunnel. The husband and father of five was last seen alive on West and Liberty streets.

About 15,000 runners retraced Siller's steps Sunday. Many participants said the annual event, which started with just 3,000 runners, helps them heal. But his relatives say it often feels like it's just the day after the attacks on the Twin Towers.

Proceeds from the run will benefit the Stephen Siller FDNY Let Us Do Good Children's Foundation. The run has raised more than $1 million over the years.

Related information:Tunnel To Towers Run