Chicago's greatest 24-hour rainfall

Dear Tom,
We just broke the record for most rain in a calendar day. What is the city's
record for rainfall in any 24-hour period?
Mark Kristoff, Lincolnwood
Dear Mark,
Chicago's record 24-hour rainfall of 9.35 inches was established during the
historic deluge that swamped the O'Hare area on Aug. 13-14, 1987. The rain
began at 9:16 p.m. on Aug. 13 and finally ended 17 hours and 29 minutes
later at 2:45 p.m. on Aug. 14. The flooding was so severe the airport was
turned into an inaccessible island. As devastating as this rainfall episode
was, it was dwarfed by Illinois' 24-hour rainfall record of 16.91 inches set
at Aurora on July 17-18, 1996. The U.S. 24-hour rainfall record is 43 inches
at Alvin, Texas, on July 25-26, 1979, while the world record is an
incredible 73.62 inches measured on March 15-16, 1952 on Reunion Island at
Cilaos, about 500 miles east of Madagascar.