The largest tornado in Chicago history hit southwest suburban Plainfield in 1990.
It is believed to be the only EF5 tornado to strike the Chicago area.
Twenty-nine people were killed and hundreds of others injured.
Architect Cliff Bender survived the tornado. He was attending a meeting at Plainfield Central High School and escaped right before the roof collapsed. He was the architect for the replacement school.
He spoke with WGN Morning News about the recent tornado in Oklahoma.