I still do not understand why some of the workers at Ground Zero didn't wear the masks that they were given. I was working in the financial district at the time, and we knew that the air in the WTC vicinity was toxic. I didn't go back to work for several weeks after 9/11, it was bad even then for some time, and you could see the clouds of smoke and other crap over NYC for months. Sometimes you could even detect it in the air of closed-off buildings, depending on the weather and wind. Many employers gave out throwaway masks to the office workers in our area. I think that I still have a couple. I cannot imagine actually working in that rubble without a heavy-duty mask for protection - at the very least. Amazingly, I don't know of anybody from the financial district that's gotten sick yet from exposure to it.