Ulrike Schwartz arrived with her children in Galtür, Austria, in February 1999 expecting to enjoy the best skiing of her life. The German family had plenty of company. The week prior to their arrival more than three thousand tourists had flocked to this small village of seven hundred residents tucked away in a steep valley high in the Alps near the Swiss border. In the midst of one of the snowiest winters in memory, the slopes surrounding the internationally famous resort were covered in the type of deep, white powder that skiers dream about.

According to the experts, in fact, there was too much snow in the mountains. It had fallen so heavily and for so long that the roads to Galtür had been impassable all week. Austrian meteorologist Erhad Berger was among those warning that, under the current...