(UPDATE 4 p.m.) The package is a science experiment that was supposed to be delivered to a nearby building.
(UPDATE 3:50 p.m.) The bomb squad has determined that the package is not a threat. The evacuation is lifted.
Earlier:
Police are at the federal building at 500 East Zack Street after reports of a suspicious package there.
The building has been evacuated and surrounding streets closed just to be safe.