those tools and expertise were at usamriid. >> narrator: usamriid-- the u.s. army medical research institute of infectious diseases. located in maryland, usamriid is the center of the army's bio- defense effort. they took the powder there to the lab of one of the army's top anthrax vaccine experts, dr. bruce ivins. >> his reputation was that of an extraordinary microbiologist. he did the truly preliminary snapshot assessments of this material because he was so good at what he did. >> he was just fascinated with the way it was just like a mist. it was so light, you couldn't weigh it. it was very dangerous stuff. >> narrator: ivins and the scientists at the army's bio-lab said this was something new. unlike the wet anthrax they worked with, the powder was dry and very deadly. >> he was the first one to describe it as "energetic." the material literally would float and waft within the bag, for instance. and so, when anyone brought a hand near the bag, a lot of these spores would migrate towards the hand. >> narrator: they knew this highly floatable anthrax was so