BATON ROUGE - Three people are displaced after a fire at an apartment building that investigators say was intentionally set. 

The Baton Rouge Fire Department said it responded to a multi-family housing unit on Avenue B shortly after midnight early Thursday morning.

Firefighters found heavy smoke and a small fire in the building's attic.  Three people who were living in the home were safely outside and no injuries were reported. 

The Baton Rouge Fire Department said the three displaced residents were living in Apartment A.

"They had light smoke visible from the roof of the apartment building. When they made entry into Apartment C, they had much thicker smoke. Through their investigation, they realized that the fire was in the attic," BRFD's Justin Hill said.

No one was living in apartments B or C.

"They were staying in Apartment A and the fire took place behind Apartment C, but it has a shared attic space and it affected them. The Red Cross is going to be assisting them," Hill said.

Apartment A suffered smoke and water damage, estimated to cost around 70,000 dollars. Investigators determined that the fire spread from a storage area.

"They found that the fire started in an outside storage room behind Apartment C where nobody was living and it made its way up into the attic," Hill said.

Firefighters say there was nothing in the outside storage room that could have started the fire. They say it was intentionally set and that is why it's being investigated as arson.

The fire was determined to be the work of an arsonist. Anyone with information is asked to contact Crime Stoppers at (225) 344-7867.