An early morning fire displaced a family of three in east Vancouver on Saturday.The fire was reported at 1:08 a.m. in the 3000 block of N.E. 186th Place, north of the Harmony Sports Complex. Vancouver firefighters arrived to find flames engulfing two exterior walls and flames through the roof on the back of the house, according to Capt. Joe Spatz.A working smoke detector had alerted the occupants to the fire, and they were standing outside when firefighters arrived.The exterior fire was quickly extinguished, Spatz said. As more fire crews arrived, they were sent inside the 3,000-square-foot home to extinguish fires in second-floor bedrooms and the attic.Crews remained on scene for approximately four hours ensuring all hot spots were extinguished.Three residents of the home plus a dog were displaced and received assistance from the American Red Cross.The Clark County fire marshal was called to investigate the cause of the fire.Camas-Washougal firefighters assisted the Vancouver Fire Department on the call.