Flames ignited at the Camelot Banquet Hall in the 8000-block of 95th Street.
Several south suburban fire departments were called to the scene in Hickory Hills to battle the blaze, which began in the kitchen.
Seven events, including Mother's Day gatherings and communions, had to be moved.
The hall's owners managed to accomodate all of the parties planned Sunday. All of the events were moved to the Hickory Hills Country Club.
Officials say the quick actions of a Hickory Hills police officer helped save the lives of the owners.
"There were two people, the owners inside, they sometimes sleep in the office. We had the police officer pound on the door to alert get them out," said Walter Sherman, Roberts Park Fire Protection District.
The owners say they are grateful to the officer, who rescued them just as the fire began.
"We are alive because of him," said Oanne Naughton.
"I heard. . . You've got to get out. . . Thank God, because two minutes later the whole place was engulfed," said Kris Drozek.
Patrons say they are relieved at the outcome.
"The main thing is I'm glad everybody is alright, no one injured. We are grateful and we will continue with son's first communion," said customer Adam Janik.
Meanwhile, the owners are reassuring customers who have upcoming events at the venue.
"I know there are brides right now that are probably panicing. Don't panic, everything is under control," said Irene Jordan.
"I was sleeping this morning received a text message from my mother saying your wedding venue burned down," said Kristen Ragan, customer.
Still, Ragan says she feels fortunate her wedding is taking place later this year.
