Joliet police said the crash happened near Washington and Ottawa streets around 4:05 p.m. The semi fled the scene of the crash.
The vehicle fatally struck a 51-year old New Lenox man at the location, police said. The man had just been released from the Will County Adult Detention Facility the same day, which is near the crash site. His identity was not immediately known.
The semi was traveling southbound on Ottawa Street and kept driving after hitting the man, police said.
The victim died due to his injuries from the crash, Joliet police said.
Police asked the public to avoid the area of Washington and Ottawa and find alternative routes. The area will continued to be closed for several hours.
Authorities did not immediately provide further information about the crash.
This story previously said the man was 21 years old based on information from Joliet police.