Firefighters in Yakima say they have recently responded to a number of fires, including some that may be the work of an arsonist. According to a reports, Yakima firefighters assisted in the attack of a garage fire at Hennessy Road in West Valley Monday. Three firefighters were treated for heat-related injuries in the attack of this fire. West Valley firefighters and the Yakima County Fire Marshall's Office is investigating to determine what caused this fire. The Yakima Fire Department responded to another fire Monday night in the alley between 7th and 8th Streets. Fire crews said they found fire coming from a garage at the alley with power lines down.