Most of the damage from the storms was south of the city. There were reports of at least 50 trees down in Oak Lawn alone.
Across the area Saturday night, ComEd says at least 11,000 customers are without power.
"The noise was so loud - there was so much power to the storm that it was scary," said Oak Lawn resident Eric George.
Across Oak Lawn, streets were closed Saturday evening, power lines down, and cleanup crews out in force. On 54th Avenue, a massive tree fell onto the Egan family's car and barely missed their house.
"Everything fell between our house and our neighbor's house. All of the trees, in this immediate area that fell... everything fell kind of between houses," said Philip Egan.
One garage was less fortunate. It was being used to house antique furniture and other family heirlooms, and Saturday night, it was a total loss.
"The foundation is probably cracked. Everything is gone," said Tim Hanno. "The whole back wall - you can't see it, but that's in the alley, which is probably why the city's going to have to come take it out."
Earlier in the day, the heat caused injury to a number of runners in a half marathon.
Police say Wrigleyville resident Zachary Gregory, 22, was taken from the race to a hospital, where he later died. No cause of death had been officially determined Saturday night.
At least ten other runners were overcome by heat and hospitalized, and eventually, the race was halted around 9:15 a.m.
"A friend of mine saw them giving chest compressions to someone who was down on the ground," said runner Julie Steffen. "There was several people that were being assisted on the side of the course."
The race organizer said runners were warned before and during the race to take it easy because of the heat. Extra water stations were also set up.
"We have ten water stations on the course that include Powerade also, we added two spray stations on the course, we added wet, cold towels on the course," said race director Jeff Graves.
The heat index was already in the 80s when the half marathon began at the South Shore Cultural Center around 7 a.m.
ABC7 reporter John Garcia took part in the run, and he said that prior to the race, he received the warning about the temperatures.
"They put the word out the night before, before we took off in the morning," said Garcia. "They reiterated that the weather conditions were going to be a potential problem and reminded us to get lots of fluids."
Saturday's soaring temperatures didn't stop more than 2,900 people from participating in the Avon Walk for Breast Cancer.
"It's been really hot, but with water, Gatorade, Avon's done such a great job at hydrating us, so it's awesome," said walk participant Cristina Solis.
Organizers set up several water stations along the 26.2-mile course.
"Well, I'm actually enjoying it, but I'm drinking a lot of water," said walk participant Charlotte Smith. "After this winter, I'm excited about summer, so we're just moving and pacing ourselves and keeping hydrated."
As the heat index reached into the upper 90s, shoppers looked for hot book deals at Lit Fest in Printer's Row.
"I mean, I was sweating bullets before, but now that there's a breeze, I'm feeling a lot better and ready to get some book action on," said Marissa Wasselek.
Thousands of people had packed North Avenue Beach to escape the heat until the storms hit and the beach was shut down. For most of the day, it was perfect beach weather, but by mid-afternoon, temperatures started to fall and eventually a storm rolled in. North Avenue Beach was closed at 3:40 p.m.
"I was sweating before I even got to the beach, and then this all rolled up, and the cold front came in, and it feels really, really good," said Colin Hellom.
This is the second time in less than a week that North Avenue Beach has been closed. On Memorial Day, it was shut down after several people suffered heat exhaustion. On Saturday, it was the threat from lightning that prompted action.
