Crews were called to Main Street early Sunday morning and had been there for much of the day watching for flare ups.
The fire took nearly three and a half hours to put out.
There is not much left of one of Mount Prospect's older buildings after a fire broke out early Sunday morning, gutting several businesses and leaving a half dozen apartment dwellers homeless.
"All the people that lived upstairs were evacuated, downstairs the businesses are completely damaged. Chamber of Commerce, Picket Fence are going to have to go ahead and be relocated someplace else because this building will come down," said village trustee A. John Korn.
Calls for help began around 4 a.m. Sunday morning.
That's when witnesses reported smelling smoke and seeing flames coming from the building located in the 100 block of South Main Street in a section of the northwest suburb's business district.
"I ran out to my car at 2 in the morning to get my book bag and there was nobody out there, it was a complete ghost town, just people plowing snow, and then just an hour later it feels like the whole block was lit up," said witness Peter Katsogianis.
Firefighters arrived to find a fire at the popular Sakura Japanese Sushi restaurant.
"I used to order from there all the time. It wasn't very busy, but they have good food," said neighborhood resident Christy Rahman.
Firefighters took a defensive stance against the fire which spread to the building's apartments above the restaurant displacing at least six residents.
"They did encounter smoke on the first and second floor and then we sent crews down to the basement where they encountered heavy volume of fire and smoke and extensive heat as they were making the stairwell," said Chief John Malcom, Mt. Prospect Fire Department.
Sunday afternoon, adjacent business Central Continental Bakery was forced to move its operations across the street to Village Hall because of the fire.
That's where grandparents Dan and Gislea Delatorre picked up a cake for their 5-year-old granddaughter Madison's birthday party.
"Somewhere there's a bowling alley with a bunch of little kids waiting for this cake," Dan Delatorre said.
They were not the only ones picking up cakes for occasions. The bakery owners said they are hoping to get back into their building in the next couple of days.