KATHMANDU, Nepal (AP) — Two record-breaking climbers have returned safely from the summit of Mount Everest, where climbing teams have struggled with bad weather and a coronavirus outbreak. Arthur Muir, a retired attorney from Chicago, has become the oldest American to scale the mountain at age 75. Also, Tsang Yin-hung, a teacher from Hong Kong, is now the fastest female climber of the world’s highest peak. She reached the summit from base camp in 25 hours and 50 minutes. There are only a few days of good weather left on Mount Everest this year, and climbing was closed last year due to the pandemic. Nepal is currently in lockdown, battling its worst surge in COVID-19.