The crater lake at the summit of Ruapehu Volcano in New Zealand has been violently expelled during eruptions. On Christmas Eve, 1953, a mudflow caused by the sudden release of the lake swept away a railroad bridge near the base of the volcano. An express train fell into the flooded river killing 151 passengers. In 1995-1996, eruptions of Ruapehu forced the closure of the ski area on its slopes. The skiers mainly complained that the gritty ash on the snow was hard on their skis.    Photo copyright R.W. Decker