CHICAGO (WLS) -- The FBI is investigating as the Everett McKinley Dirksen United States Courthouse was placed on lockdown on Monday. ABC7 was at the scene at about 11 a.m. at 219 South Dearborn Street. The public is being asked to avoid the building for the time being.

A man reportedly armed with a knife and barricaded in the lobby of the Dirksen Federal Building was transported by ambulance Tuesday evening following an hours-long standoff.