Authorities responded to the Dirksen Federal Building in Chicago on Wednesday after a suspicious package was delivered to the facility.
According to the Chicago Fire Department, a letter addressed to one of the judges in the building, but it’s unclear which judge was the intended recipient.
The letter had some sort of substance in it, fire officials said, but the substance was determined not to be hazardous after examination. No one was injured, according to authorities.
The letter has been turned over to authorities and the United States Postal Service, and an investigation is still ongoing.