'Terror in the dust:' Toxins from Twin Towers believed to be killing first responders

Nearly three thousand people died on September 11th when the Twin Towers came crumbling to the ground, although many New Yorkers believe that this figure needs to be adjusted higher due to what they call the "terror in the dust."

A decade after the disaster, many believe that the toxins contained in the dust that blanketed the Ground Zero site are still killing 9/11 first responders.

Dr. Sanjay Gupta brings a sample of this dust to American Morning today and explains what is in the substance that could make people sick.