Fire forces evacuation of Old City building

September 5, 2013 10:12:56 AM PDT
A 20-story office building in Philadelphia's Old City section was evacuated Thursday morning due to fire.

Firefighters responded around 9:25 a.m. to the 300 block of Chestnut Street.

When crews arrived they found smoke coming from the building, prompting the evacuation.

People have since returned to the building.

So far, there is no word on the nature of the incident.