Energy Safety determined that the microwave oven was the most likely cause of the fire, but could not determine this reliably enough to exclude other possible ignition causes.
The Fire and Emergency report listed the fridge as the likely cause; as the fridge is an appliance that would have normally running in the early hours of the morning when the fire occurred. However Energy Safety did not share this opinion on the evidence examined at the scene.
Intense heat immediately behind the microwave created a hole in the wall partition at that point and the fire pattern also supported the microwave oven next to the fridge as a point of origin. Although the microwave was found to be empty of food, the elderly victim was known to be confused and was fully dressed at the time of the fire.
Further examination of the microwave found evidence that the large magnetron capacitor had ruptured, this was considered by Energy Safety to have been the point of fire origin within the microwave oven that aligned perfectly with the hole in the wall. This combined with the fire pattern seen, led Energy Safety to consider the microwave as the most likely point of origin. However Energy Safety accepts that the capacitor could also have ruptured as a consequence of the fire, from a point of origin outside of the microwave oven.