Waterloo officials have released more information on the illness that hospitalized the city’s police chief over the weekend. Paramedics were called to the home of Thomas Jennings Sunday morning on a report of an unknown medical problem. Emergency crews took Jennings to a local hospital, and later flew him to the Mayo Clinic in Rochester, Minnesota. It was there where doctors determined that Waterloo’s 49-year-old police chief had suffered a heart attack. On Monday, Jennings underwent a cardiac catheterization, a procedure that’s done on patients being considered for heart surgery or angioplasty. According to a Waterloo police news release, the procedure was successful. Jennings remains hospitalized in Rochester. His condition is not being released.