It's not every day you come across firefighters setting fires to homes.

But that is what a number of departments were doing in Moorhead.

Across the street from the Clay County Courthouse four homes were set on fire over the course of the day.

Each home was set up, and then set ablaze.

The homes are set on fire multiple times, each time exemplifying a way a fire can start.

"We had ones from candle fires or just a house keeping issue inside of a kitchen and then we had some intentional ones where we had those set also," says Moorhead Fire Marshall Chad Stangeland.

There were even some timely examples.

"They showed how the difference between a battery exploding like a cell phone battery exploding versus what it looks like when it's been involved in a fire like if someone left it on a couch," Captain Gary Larsen of the Moorhead Fire Department.

They then have fire investigators come in the homes after they've been put out.

They are shown how to identify what started each fire.

"That's the benefit of having us all work together as a team is we have different points of view we're looking at differently,"Stangeland.

Unlike the other three houses which were burned and used as a refresher course for already instated fire investigators, this home is going to be burned and tomorrow aspiring fire investigators are going to come in and use this as their certification test, determining what caused the fire.

"We're doing the burns and then it will sit overnight then tomorrow they will come in and they will do investigations in here to get certified as arson investigators," says Captain Larsen.

This test is the final one in the process of becoming and investigator.

"In a group usually three to four people you will go in and do a fire investigation on one of the fires like the one we just set and put out. They'll have to determine how it started, interview people, and go through the whole process," says Captain Larsen.

The fire investigators in training will have to turn in a full investigation over the next few months.