SKIATOOK, Oklahoma - Firefighters in Skiatook are trying to figure out what caused a fire that destroyed a duplex on Wildhorse Street Wednesday morning.

Firefighters said the house is a total loss, leaving two people homeless.

Skiatook firefighters said the fire had already spread to the attic by the time they arrived. Neighbors said it was a scary sight.

"It was pretty crazy. It was actually bigger, a lot bigger here than anything I've ever seen," neighbor Richard Scott said.

The flames soared into the sky as several departments worked to put out the fire.

Fire Marshal Robert Nail said cold temperatures made for dangerous conditions.

"It's 19 degrees out here - water freezes, we use a lot of water, so the slip and fall hazard were immediately a problem," he said.

Scott said a neighbor told him about the fire and he went to check it out. He said you could feel the heat from the fire just a few houses away.

"Whenever I stepped out of the house, I couldn't see the house directly but it was actually up over our neighbor's house," he said.

The fire left minor smoke damage outside the next-door neighbors' homes.

Scott said he was glad it didn't spread any further.

"I was really concerned that maybe it'd spread because we're only two houses down, so I was hoping it wouldn't spread, you know. But the wind was blowing the other way, so I was hoping it wouldn't go anywhere else either," Scott said.

Firefighters said the duplex's other unit was vacant.

The cause of the fire is still under investigation.