Two pilots, a doctor and another crew member were killed when their rescue helicopter may have hit a zipline in the United Arab Emirates. The helicopter had been dispatched to airlift a man who was injured at Jebel Jais Mountain, the site of the world’s longest zipline. Video showed the helicopter flipping end over end as it crashed and exploded. The aircraft belonged to the UAE’s National Search and Rescue Center. The three crew were UAE residents but the doctor was from South Africa.