Aug. 03--The National Weather Service says a tornado packing winds of 90 to 100 mph touched down in the Grayslake area Sunday night.
Citing preliminary information, the weather service classified the tornado as an EF1, the second-lowest category. The determination was made after survey crews inspected an area from Round Lake to Grayslake.
"Some of the damage is indeed damage that would be caused by a tornado," said Kevin Donofrio, a meteorologist with the weather service.
The tornado was spawned by the second of two strong bands of storms that crossed the Chicago area Sunday.
The storm that raked Lake County hit around 8 p.m. from the north ahead of a strong cold front, tearing off sections of the roof at Grayslake Central High School and tossing them onto Lake Street.
Other damage included:
--A wall of a Portillo's restaurant under construction at Gurnee Mills that collapsed, sending debris onto Ring Road.
--A stretch of downed trees and power lines 4 to 5 miles long through Grayslake.
--Hail damage to some Envoy Air planes at O'Hare International Airport.
--An early end to Lollapalooza. Florence + the Machine, Bassnectar, Kygo and Nero shortened their sets, and more than 89,000 fans exited Grant Park a half-hour early.
Grayslake fire Chief John Christian said the storm was one of the worst he's ever seen in the area, though he couldn't confirm early Monday whether a tornado had touched down.
"It's hard to say, it happened so fast, but based on the amount of damage certainly if it's not a tornado, it's very significant winds," he said at a news conference.
Temperatures dropped by 10 degrees or more as the second wave of storms moved through, according to the weather service.
It went from 85 in Waukegan at 8 p.m. to 75 at 9 p.m. to 66 at 10 p.m.
The first wave hit midafternoon Sunday from the west, packing high winds and large hail and leaving a trail of damage from the town of Elburn to Rogers Park in Chicago.
--A tent at a Wood Dale festival toppled over, killing a man and injuring about 20 people, three of them seriously.
--A sports dome in Rosemont, where the Chicago Bandits softball team plays, collapsed, but no injuries were reported.
--In Chicago, Lollapalooza was evacuated at 2:35 p.m. About 48,500 fans and 4,500 staff, artists and vendors were told to seek shelter. The gates reopened at 3:30 p.m., and music started again at 4 p.m.
--In Rogers Park on Chicago's Far North Side, trees were blown down by high winds and blocked streets in the 6500 blocks of Bosworth, Greenview and Newgard avenues, as well as many other areas. A man in his 60s suffered head injuries from a falling tree limb.
Much of the damage from the first wave was likely caused by straight-line winds or microbursts, according to Donofrio.
The forecast for the first part of the week was for cooler conditions and sunny skies.
