Some 30 employees working at the State of Michigan Operations Center underwent decontamination after a suspicious letter containing a white powdery substance was delivered to the building.
Eaton County's sheriff's officials were called to the Operations Center after employees advised them of the letter.
According to authorities, the letter appears to have been mailed from Pakistan.
Officials say they've received more than 100 calls in the past year regarding powdery substances. None have turned out to be anthrax, or any other dangerous substance, however, they say they will continue to take necessary precautionary measures.