The Climbers Who Saw Disaster Coming
David Bernays and Charles Sawyer documented Glacier 511’s instability after climbing Peru’s Cordillera Blanca in 1962. They warned local authorities about the potential collapse but received little response. Peruvian officials, recovering from an earlier avalanche, lacked funds for proper monitoring. Eight years later, an earthquake triggered the glacier’s collapse. The resulting avalanche buried the town of Yungay under 80 million cubic feet of debris on May 31, 1970, killing 25,000 people.
