Three persons died of suffocation in Quetta on Tuesday. Police said three first cousins slept on the night between Monday and Tuesday without turning off their gas heater in an airtight room in Killi Abro in the outskirts of Quetta. The heater consumed the oxygen in the room and caused their death. Two died during the night while the third died in the hospital. Neighbours found out next morning people when police shifted the bodies to hospital for autopsy. Police handed over dead bodies after completing legal formalities.