Lieutenant Patrick Hannon, 51, was rushed to Mercy Medical Center Saturday morning. He could not be revived. An autopsy found he died of natural causes.
His wife, Michelle, is a paramedic with the department. They have two children.
Visitation is Tuesday from 3 to 8 p.m. at Blake Lamb Funeral Home in Oak Lawn. The funeral mass will be Wednesday at 10:30 a.m. at Saint Barnabas Church, 10134 South Longwood in Chicago.