The number of house fires in Ottumwa has plunged in 2018, and the drop means the rumors about a serial arsonist in 2017 may have had some truth to them. Fire Chief Tony Miller said there were 26 structure fires in the first half of 2017. That was down to only 15 in the first six months of this year. “We’ve had a considerable drop,” he said. “We had a lot of questionable calls last year.” A number of the house fires last year were in buildings that had no utilities connected. When both electricity and gas lines are out of the picture, there are only so many ways a fire can start. Add to that the fact some were repeat calls and others in a concentrated area, and suspicions were strong that at least some of the fires were set intentionally.