UPDATED 08/02/11 11:58 a.m.
CHICAGO (CBS) -- The suspicious substance at an envelope sent to the Daley Center courthouse and office building downtown turned out to be powdered drywall.
A Hazardous Materials response was called around 10 a.m., when an envelope of white powder was discovered in the Cook County Clerk's Vital Records office, in the Pedway level of the Daley Center at 50 W. Washington St., authorities said.
Authorities were also concerned because the address name on the label for the envelope was "Mr. Wrong."
The staffer who opened the envelope immediately notified a supervisor, who called 911, clerk's office spokeswoman Courtney Greve said.
The office was quarantined while a Fire Department hazmat crew investigated and found the substance to be harmless.
No one was sickened or injured.
White powder delivered via mail has caused alarm across the country ever since a rash of attacks in the fall of 2001, in which several news media offices and the offices of two Democratic U.S. Senators received anthrax-tainted pieces of mail. Five people died 18 others became sick as a result.
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