A fire that leveled a house in Millinocket after setting off thousands of rounds of ammunition appears to have started because of a faulty wood stove. But the fire chief says there’s so much damage, they’ll probably never know for sure how it began.The fire on Medway Road was called in about 1:30 p.m. Thursday when the homeowner, Jamie Mackin, returned to the house. Chief Andrew Turcotte says firefighters were concerned when they first arrived and heard explosions. They quickly learned Mackin is an avid hunter and the firing sound was ammunition going off. The fire was so intense, crews had to work on protecting the surrounding buildings. One of them was also damaged.At least two dogs died in the fire and third one is still missing. One dog managed to escape.