Wind may have caused a scaffolding to break loose from a Hyde Park building leading to the death of a worker.
David O'Donnell, 27, of Oak Forest, was killed and another construction worker was seriously injured after falling nine stories, ABC7 reported.
The crew was on a site on the University Of Chicago Medical Center campus.
The nearest weather station at Midway Airport reported wind gusts of about 33 miles per hour around the time of the fall.
O'Donnell's father questioned why they were on the scaffolding on the windy day.
His son was a union technical engineer.