Investigators from the Los Angeles Police Department responded to Los Angeles City Hall Monday afternoon after someone reported a white powdery substance inside the building. Initially, firefighters with the Los Angeles Fire Department responded to 200 North Spring Street at around 12:08 p.m. for a chemical investigation. Someone had reported white powder in a sealed bag in the mail room. Stream Los Angeles News for free, 24/7, wherever you are. WATCH HERE WATCH HEREOne person was assessed, but not exposed to the power.