came in banging on the door and they said a plane just hit tower 1. this is where tower 2 was at the time. i'm standing in front of building. there was this enormous explosion above me. i could hear them yelling that a second aircraft had just hit tower 2. at that point i realized we were under attack. >> i worked for the city of new york. volunteer firefighter for 23 years. during the events of september 11th. i had a need to come down here and help. >> this museum is off the footprint of where everything happened. it can amongst everything that was here. almost 18 years ago. >> one of the first things you will see here is one of the last known pictures taken of the trade center at about 8:30 a.m. on september 11th, 2001. >> and that's what this picture represents the blue sky. how calm everything was. how beautiful everything was. >> this is lady liberty that