Fire officials say part of the federal court building in Philadelphia was evacuated for about an hour this morning after the discovery of a letter containing a threat about anthrax, but nothing hazardous was found.
Executive Fire Chief Richard Davison says crews responded to the courthouse in the city's historic district about 9:25. He says people had to leave the second floor, but those on other floors were allowed to remain.
Fire officials investigated and didn't find anything hazardous, so the all-clear was given about an hour later. People have been allowed back inside.
The FBI is investigating.