South Korea grounded an ageing fleet of military helicopters on Monday after a chopper crashed during a training exercise and killed two people on board. The AH-1S Cobra was training for emergency landings when it “crashed due to an unidentified cause” in Gapyeong county west of Seoul, the army said in a statement. Two service members were taken to hospital and later pronounced dead. Photos in local media showed the helicopter’s crumpled fuselage lying on a rocky river bank. “Following the...