Downers Grove police were flagged down at about 12:50 p.m. in the 800-block of Curtiss Street.
Two contractors became trapped while cleaning the sewers for the city when strong storms brought heavy rain to the area.
Downers Grove fire crews rescued one of the contractors, but another remained trapped as of 5:45 p.m. First responders have not yet made contact with that person.
The contractors' conditions were not immediately known.
Street closures are in place as the rescue mission continues.
Officials did not immediately provide further information.
This is a developing story. Check back with ABC7 for updates.