Tomorrow is the Tunnel to Towers Run, in honor of firefighter Stephen Siller. When he heard the World Trade Center was attacked, Siller, off-duty and heading to golf with his brothers, ran from Brooklyn to lower Manhattan with 70 pounds of equipment. Siller was last seen at West and Liberty Streets, but his memory has been honored with a 5K run that mirrors the route he made on 9/11: The race starts at 9:30 a.m. "in Brooklyn on the Gowanus approach to the Brooklyn Battery Tunnel," and then through the Tunnel, "north onto West Street, left onto Liberty Street, to Battery Park Esplanade, right (east) North Esplanade(south) onto West Street and finishing at West & Vesey Streets." Last year, 25,000 people participated.