Broad Street is open to traffic after an anonymous call placed to 911 at 7:41 a.m. threatened that there was a bomb in a blue public mailbox at Broad and Cherry Streets.

Yellow hazard tape cordoned off the main thoroughfare between Race and Arch Streets from 8 a.m. to just after 10 a.m.

Nearby buildings were evacuated as officers from various districts responded to the scene.

The Bomb Disposal Unit, which deployed a robot, set off a controlled explosion about 50 feet from the mailbox .

Two engines from the city's Fire Department were also on location before the area was declared safe at 10:21 a.m.

Contact Gene D'Alessandro at 215-854-2443 or gdalessandro@phillynews.com.