The Heat Is Online

Storms Cut Power to 852,000 People in Chicago

852,000 lose power in Chicago-area storms

'One for our record books,' utility spokesman says of outages, July 12, 2011

CHICAGO —  A powerful front of thunderstorms packing winds as strong as 75 miles per hour raked Chicago during the morning commute on Monday, knocking out power to 852,000 customers — the most here in at least 13 years.

"It's one for our record books," said Tony Hernandez, a spokesman for the utility company ComEd.

While the nation's third largest city was recovering from the sudden storm, much of the rest of the country was experiencing stiffing heat, with one man dying of heat stroke on Sunday night in southern Illinois.

The body temperature of Mitsunari Uechi, of Granite City, was 104 degrees when he arrived at the hospital. The air conditioning at his home was not operating.

The Chicago area storm also prompted the National Weather Service to issue a rare warning of tidal wave-like conditions on the shores of Lake Michigan. Strong waves hit the shores and there were major fluctuations in waves. The warning remained in effect for the Indiana shores of the Lake Michigan until 8 p.m. local time.

By Monday night, ComEd reported that 463,000 customers were still without power in the region. It could take days to restore power to all homes and businesses, it added.

The storms, which passed through the Chicago area quickly, downed numerous trees and power lines, and prompted delays on commuter train lines of up to three hours.

The storms also snarled air traffic at the region's main airports and delayed flights by almost an hour.

The Chicago Department of Aviation said delays at O'Hare International Airport were about 45 minutes. At Midway Airport, delays were about 50 minutes.

Airlines with hubs at O'Hare and Midway said the morning storms could delay flights all day throughout their systems.

"O'Hare was shut down for 48 minutes this morning due to heavy storms," said Ed Martelle, spokesman for AMR Corp's American Airlines, which has a hub at O'Hare.

Chicago was also under one of the heat advisories in effect in more than a dozen states on Monday, with temperatures expected to climb to potentially dangerous levels.

Thermometers will hover near the 100-degree mark in the central and southern plains and middle and lower Mississippi Valley, according to the National Weather Service.

In some places, heat index values exceeded 115 degrees.

Heat illnesses are possible in areas with hot temperatures and high humidity. Weather experts recommend drinking plenty of fluids, staying out of the sun and staying in an air-conditioned room.

Heavy rains are a concern for the area along the Missouri River, where there already is flooding. More rain could result in continued and prolonged flooding.

Reuters contributed to this report.