>> right then in there i knew it. this was going to be the worst day of my life as a firefighter. >> go to the trade center. >> immediately i knew this was not an accident. >> oh my god. chief pfeiffer made the first initial report. >> looks like the plane aiming towards the building. >> when we are passing it, looking up, it is like the world just stopped. >> we have something that has happened here, planes with an awful lot of smoke. whatever occurred had just occurred within minutes.