The worker, Francisco Chavez, 40, was underneath the mower, which was supported by a jack. As he was attempting to fix a hydraulic pump, the lawnmower toppled off its support, CBS Radio in Chicago reported.
The incident took place at about 3:55 p.m. local time. Chavez was taken to a local hospital where he was pronounced dead about a half hour later. The death, ruled an accident by the Cook County Medical Examiner's office, was attributed to head injuries cause from the lawnmower slipping off the jack.