Grant County sheriff’s detectives are investigating a triple homicide that occurred late Monday in Mattawa near the Columbia River, said Undersheriff John Turley. Deputies responded to a call of gunshots about 9:15 p.m. Monday at a residence in the 21000 block of Road 24.7 SW, about two miles outside of Mattawa. One man was found dead at the scene. A second man died in an ambulance shortly after emergency crews arrived, Turley said. A third male victim was found on a nearby roadway, and emergency crews were unable to revive him, the undersheriff said. The names of the victims were not initially known. Turley said detectives are looking into the possibility of drug or gang connections. The Washington State Patrol crime lab is assisting. Mattaway is located about 16 miles south of the Interstate 90 bridge at Vantage.