It's a "Sorry, we're closed" sign, which is leaving people confused, and still hungry.
"It's open when I come to work. It's open when I go home. It's open all the time," said customer Caryn Chrisman.
"We come here every morning for breakfast, lunch and dinner!" said Jake Bellis.
"Why is this McDonald's closed?" asked customer Michael Corzine.
But what they don't know, might take away their appetite.
The restaurant is linked to possible salmonella contamination.
"Anything where animal feces can touch other things that is where you can find salmonella," explained McLean County Health Department's Assistant Administrator Cathy Coverston Anderson. "Or, human feces can touch other things. That's where you find it."
The McLean County Health Department and the Illinois Department of Public Health are investigating the case.
They say early results indicate it might not be caused by food, suggesting it is being passed by people.
"We tested their surfaces and their surfaces are fine," said Communications Specialist Kera Simon. "Now we're to the point of asking all employees and managers to be tested themselves as carriers.
McDonald's will remain closed until its staff gets checked out.
Meantime, the other question remains...
Where will people work?
"Hopefully they will find a job," said customer Jake Bellis. "So they can have a good Christmas. At least try to provide for their families and get them what they need."
But until the restaurant comes back clean, owners say it's better to be safe, than sorry.
Testing could take several weeks.
McDonald's is trying to figure out a plan to get people back to work.
The franchise owners issued a statement saying the health of customers and employees is a top priority and that the restaurant is cooperating fully with the investigation.
The health department is also looking into other local cases.
Symptoms include diarrhea, abdominal cramps, and fever.
The bacteria cause more hospitalizations than any other foodborne germ.
Doctors recommend washing hands thoroughly to prevent illness.