Residents of the Sienna condo complex at 1718 Oak St. have been forced to evacuate their homes afterÂ a parking deck on the site partially collapsed Friday night.
A Sienna construction site webcam captures the collapse scene.
City officials say the top level of the parking deck collapsed, sendingÂ a 70 foot x 20 foot section of the parking rampÂ falling three stories to the basement level.Â And a secondary collapse occured shortly after police and fire units arrived on the scene.
City structural engineers determined the parking structure and theÂ adjoining condominium building were unsafe and ordered a complete evacuation.
Residents of the 55 condo units were relocated. Limited access with fire department escorts was provided to allow residents to collect their personal belongings.
A fire fighter suffered a minor hand injury and several cars were damaged.
The cause of the collapse is under investigation. The Chicago Tribune reports that Tom Roszak, principal owner of Roszak/ADC, which developed the parking deck and condominiums, said the top level of the parking deck was being landscaped and that may have been a factor in the collapse.
The Sienna complex is being built in several phases, andÂ the parking garage and the evacuated units reportedly were completed about a year ago.
Mr. Roszak told the TribuneÂ he expects residents can return in about a week, but the parking garage, used by residents and employees of an office building across the street, will take much longer to re-open.