POST FALLS, Idaho -

As part of National Fire Prevention Week, off-duty firefighters have teamed up with Domino's in Post Falls to help make sure that people in the area have fully functioning fire alarms. If they do, their pizza is free.

"We are here to check your smoke detectors. If you would like us to and if they are working Domino's has graciously picked up your tab for your pizza," Troy Speziale with the Kootenai County Fire Department said.

The arrival of the firefighters in a 1940s fire truck caught some Domino's customers, like Ryan Matheny, by surprise.

"We decided not to cook tonight, then you got 5 people by your door, the house is a mess," Ryan Matheny said.

But good news for Ryan, he got a free pizza because all of his smoke detectors worked.

"Being on the top floor it will be nice to know that we will be alerted and be able to get out. It gives you comfort when you go to bed," Matheny said.

And there's a chance that more people will be getting free pizza over the next two days. Firefighters from Kootenai County Fire Department are expected to be out again with Domino's Wednesday and Thursday night in Post Falls.

If customers' smoke detectors don't work, firefighters will replace the batteries or even the smoke detector for free. However, customers will have to pay for their pizza.