COLUMBIA, Mo. -

The Columbia Fire Department has ruled the cause of a fire at Columbia restaurant last week as undetermined.

The owner's of Mackenzie's Prime, Charlene and Chris Thompson cleaned up their restaurant last Thursday.

"All day today we've  been trying to clean, get things out of the coolers, because we have no electricity," said Charlene.

Chris said, "I grabbed my reservation book as soon as they let me in the building.  I started calling people to tell them and hoped they had enough time to make other plans."

Chris also said he isn't sure, but has his suspicions of who started the fire.

"The homeless problem is a problem.  I don't know if that's the cause, but it's odd that it started several hours after we were gone and in a spot where we know they hang out," said Chris.

Their lease was up at the end of June, but the fire has closed the restaurant unexpectedly.

Investigators were looking for the cause of a fire that damaged a downtown Columbia restaurant.

Firefighters were called out to Mackenzie's Prime at 131 10th Street just before midnight Wednesday.

Crews found a shed attached to the rear of the restaurant on fire with some extension to the main structure.

While firefighters were working to put out the flames an energized electrical line dislodged from the building, struck the ground and began arcing.

Fire crews had to back away until Columbia Water and Light arrived to disconnect power to the energized line.

Damage was estimated Thursday morning at $20,000. No one was injured.