The sinkhole swallowed three cars at 96th and Houston in the Jeffery Manor neighborhood. It started to open around 5:15 a.m.
A man also fell into the sinkhole, but authorities were able to get him out, according to eyewitness Laide Giwa.
Chicago Police Department spokesman Mike Sullivan says the injured man was driving when the road buckled and caved in. He was taken to Northwestern Memorial Hospital with non-life threatening injuries. The other two cars were parked.
A cast iron water main dating back to 1915 broke during the massive storm. The hole spanned the entire width of the road and chewed up grassy areas abutting the sidewalk.
Tom LaPorte, a spokesman for the city's water department, said the force of the heavy rain or the movement and weight of the rain-soaked ground could have caused the pipe to crack open.
Crews worked into Thursday afternoon to shore up the sides to prevent any further collapse.
The Associated Press contributed to this report.