On Saturday, April 21st at 12:08 PM, District fire units responded to a reported structure fire on Rio Del Mar. A full first alarm structural fire assignment was also dispatched which includes fire units from Vallejo, Napa County and Napa City FD’s. Engine 11 arrived on scene first and initiated an offensive fire attack from the front door. As resources arrived additional tactical objectives were commenced such as protecting exposures. Due to ammunition being present in the residence a transition to a defensive strategy became necessary during the fire suppression operation. Within approximately a half hour the fire was contained with the overall structure and a significant portion of contents saved. There was one minor injury to a firefighter but no injuries to civilians. Crews remained on scene for salvage, overhaul operations and investigation of cause and origin for the next several hours. All units were clear at 8:07 PM.