i'm denis leary. the entire nation gasped when the twin towers, reaching high into the sky, single bottoms of success were brought crashing down when two jetliners flew directly into them. here are the names of the almost 3,000 innocent lives that were lost that day, including 343 of new york's bravest. cnn is honored to bring you the epic film " 9/11" that was born when two brothers with film maker james hanlon was shooting a movie about a rookie fireman in the nypd. it was transformed into a gripping account of what happened while the towers burned and then fell. they kept their cameras roeblgs capturing historic footage, heading towards danger in the area that became known as ground zero zero. >>> when you work in the firehouse seven blocks from the two tallest buildings in new york, you get to know every step, every staircase, every story. >> couldn't get too close to that. >> i'm james hanlon. i'm a film maker and a firefighter at leader one downtown. during the summer before 9/11, there were day