Investigators are scheduled to begin sifting through the ashes inside the former Dickson County Ambulance Service building today trying to determine a cause of last week’s fire. Dickson County Mayor Bob Rial said the West End Avenue building “appears to be a total loss” after an early morning fire gutted the interior and engulfed the roof last Thursday. Rial said some of the equipment inside the building might be salvageable. Dickson Fire Department Fire Marshal Robby Street said an investigation to determine a cause of the fire will begin today. Flames were reported coming out of the building around 4 am last Thursday but firefighters on the scene said they believe the fire had been burning for “a while” before it was discovered. Since the ambulance service moved to Cowan Road, the county has been using the building for storage and offices for its facilities maintenance department. The county commission voted earlier this year to allocate almost $23,000 to a project to remodel the interior for offices and a backup Emergency Operations Center and put a security fence around the property. “The work was about 75 percent complete,” Rial said in an email. The mayor said preliminary information indicates the fire might have started in an area that was not a part of the remodeling project. Street said the investigation into the fire was delayed after the fire department spent a good portion of the rest of that day at a fire on Old Pond Lane and then by the heavy rain that moved through the area at the beginning of the week. A fire at an open-air shed that housed farm equipment and rolls of hay on Old Pond Lane kept firefighters tied up for most of Thursday. A passing school bus reported the fire shortly after 7 am. Street said the fire was started when a tractor’s electrical system shorted out and caused the tractor to catch fire, which then spread to the hay and other equipment. “Everything under the shed and the structure itself was a total loss. Fire crews stayed on the scene most of the day as the hay bales burned out,” Street said.