Montgomery County Neighborhood shut-down after powdery substance dropped from plane Email story to a friend November 15, 2001 Reports of a powdery substance dropped from planes has shut down an entire subdivision. It's happening Thursday night in the northern part of Clarksville off 101st Parkway. The neighborhood is cordoned off. Police, sheriff, and TEMA officials are on the scene. Police say there were reports that two planes dropped the powder earlier Thursday evening over the Northpark/Northwind subdivision. Field tests done on the powder came back negative for anthrax, but the state lab is on standby. Clarksville Mayor Johnny Piper ...