Mount Everest saw an unprecedented rush of climbers yesterday, with a record 274 people reaching the summit from the Nepali side in a single day — the most ever to stand atop the world’s highest mountain in 24 hours. Rising 8,849 metres, Everest sits on the border between Nepal and China’s Tibet region, and expeditions can approach the peak from either side. But expedition operators said no climbers attempted the mountain from the Tibetan side this year after Chinese authorities did not issue permits. Among those who reached…