EVANSVILLE, Ind. (WEHT) — Officials in Evansville are investigating after a storage facility caught fire early Monday morning.

The fire started just before 6 in the morning at Stor-N-Lock on Kratzville Road.

Witnesses on the scene told Eyewitness News someone had been living in one of the units, but it’s unclear if they are linked to the fire.

When firefighters arrived, they said flames were already overtaking several units.

“The fire quickly escalated and it ran the whole roof line,” said District Fire Chief Eric Eifert.

He said several things prevented them from getting the fire out quickly.

“This was a completely locked structure. Each unit had a lock that had to be cut or a door that had to be cut which prevented access to get in there,” said Eifert.

We’ve been told there may have been propane tanks in the facility.

Because firefighters did not know what was in each unit, they fought the flames from the outside. Crews spend all morning at the scene watering down hotspots.

Even though officials say the fire was extinguished just before 7:30, Eifert said it was still unsafe for them to enter.

“We organized a crane or a backhoe to come and demolish it.”

This allowed firefighters to get to the hotspots underneath heavy debris.

Several storage units to the west end of the building were saved from fire damage due to firefighters’ efforts. No one was hurt. The cause of the fire is under investigation.