KARACHI          -    Four brothers were killed by gas suffocation in Landi area, Karachi district, police and Rescue sources reported on Tuesday morning.  According to details, four persons identified as Noor Hamad, Umer, Usman and Hamza, hailing from Pishin area of Balochistan province, living in a house situated in Kanta of Landi area, Karachi were found dead in their room.  As per police sources, the ill-fated brothers left the generator open last night and the smoke emitting from it filled their room, resulting in their death on the spot.  The Rescue and Police have shifted the bodies to Jinnah hospital for necessary  procedure.