A house fire in the old west end Thursday morning has been ruled an arson. Toledo firefighters responded to the three-thousand block of Parkwood Avenue just before 6:30am. Firefighters say they immediately went into defensive mode. No one was inside at the time. Fire crews were able to prevent the fire from spreading to any neighboring homes. This is the second time the house went up in flames in the last twelve hours. City building crews will be out later this morning to demolish the home.