Fire investigators determined that last night’s house fire in the Ravenna neighborhood was accidental. The call was dispatched at 10:40 pm to to  7340 23rd Avenue Northeast. Firefighters found flames coming from the back of the house when they arrived. The residents were able to get out of the house safely. The fire started in a bedroom when an oil heater malfunctioned. The estimated damage to the home  is $250,000.