Nepal’s catastrophic flood disaster has triggered one of the country’s biggest helicopter rescue operations. With roads and bridges destroyed across Rasuwa and Nuwakot, helicopters became the only lifeline for thousands stranded in remote mountain areas. More than 4,000 people have been airlifted in hundreds of sorties through narrow, treacherous gorges. Rescue officials say the operation has been even tougher than some Everest rescues, highlighting the enormous challenges faced by emergency teams.