CHARLESTON, W.Va. (WSAZ) -- Making their way amid the rubble, investigators examined what a destructive fire left behind on Charleston's west side. It ripped through an empty house on Glen Street Friday night, giving neighbors a scare.

"The tree was on fire and the whole back of the house was on fire," Donna Moles said. "I was worried that pieces were popping over and coming next to my house."

Investigators say it started in a shed behind the home and then quickly spread to the attic inside. Crew were able to stamp it out before it did any more damage - something neighbors like Donna feared.

"It looked like it was going to catch my house on fire and burn down utility wires," she said. "I was worried to death."

What caused the spark is still a mystery, but investigators say they'll get to the bottom of it.

"There was definitely a human involved," fire investigator Wes Smith said. "We're just not sure whether it was intentional or accidental."

This marks the third suspicious fire on Charleston's west side in the past week.