as an ambulance pulls in, dozens of medical workers rush up to it. but it's a carnage that's just beginning. everybody here, the emergency service workers i spoke to have been down into the world trade center site say this is just the tip of the iceberg. there's going to be massive amounts of casualties. >> what are they telling you about people? were there many people inside the building, or is that just -- is it just too early to tell? >> it's too early to tell. there were certainly, you know, probably hundreds, even thousands of people in the buding even though it was before 9:00 on the start of the usual work period because it's just such a large area. so the number of casualties is just enormous. they're just beginning tout sor it out and getting to the first few they can get to. but the ambulances are coming in. they're lined up, every ambulance in new york has been summoned. they're standing in a queue. they go in as soon as they can get a victim and bring them up here right away. >> bob, we're also looking at the lower end of manhattan as a relt of the collapse of one world trade center. that whole financial district is