Emergency crews are sifting through rubble at a suburban Pittsburgh shopping center where part of the roof collapsed in front of a dollar store.

Authorities say there are no reports of injuries at the Dollar General store at Hillcrest Shopping Center in Bethel Park.

Television news video shows a section of the roof in front of the store in ruins. It was not immediately clear if the facade or other sections of the store are damaged, too.

The incident was called in about noon. Authorities aren't saying what caused the roof to fall.

Bethel Park is a suburb just south of Pittsburgh.