DEVELOPING: Philadelphia rescue crews are searching frantically for survivors after a building collapsed in downtown Philadelphia Wednesday morning, with initial reports indicating up to 10 people may trapped under the debris, MyFoxPhilly.com reported.

Police Commissioner Charles Ramsey said police are "still pulling people out," and there is no way to know for sure how many people remain trapped. News helicopters have been asked to move from the scene because it is hindering the crews' ability to hear screams.

It was considered a "hands-only" operation with no heavy equipment for about the first hour. It was firefighters with buckets moving bricks. A team of four search dogs are also deployed at the scene.

The collapse occurred on 22nd and Market streets, in the city's downtown area. Dozens of firefighters and emergency personnel are at the scene actively searching for victims. At least three people have been pulled from the rubble and transported to the Hospital of the University of Pennsylvania. Initial reports indicate there were 11 total hospitalized.

The collapse involved a Salvation Army corner thrift store and a four-story building next door with a sandwich shop on the first floor. It's not clear whether any other adjacent buildings were damaged.

The building's facade and side wall came down shortly before 10:45 a.m.

MyFoxPhilly.com reported that it appears firefighters are split into two groups: one group is focused on the back of the collapsed building while the other group is inside the Salvation Army.

The Salvation Army next door was undergoing demolition, but it is not immediately clear if there is any connection, The Philadelphia Fire Department told Fox News. Police, however, said it appears the collapse was the result of an industrial accident.  

Click for more from MyFoxPhilly.com