A freak storm killed 21 ultra-marathon runners in northwest China after freezing rain, hailstones, and strong winds struck the Yellow River Stone Forest. Many of the 172 racers collapsed due to hypothermia, and several left the course to find shelter. Several hours into the race, which started under sunny skies, temps plummeted and strong winds picked up. Local authorities dispatched 1,200 people to search for the athletes. Early Sunday morning, 151 had been rescued and 21 were confirmed dead.