The Joel D Valdez Main Library was evacuated at around 5:50 p.m. Thursday night according to Sgt. Peter Dugan with the Tucson Police Department.
Someone at the library on Stone and Alameda found an envelope with suspicious debris and some writing on it.
Tucson police bomb units and the Tucson Fire Department are on scene and evacuated the building.
At around 7:30, the library was given the all clear.