http://www.newsweek.com/volcano-deadly-nevado-del-ruiz-1798011

Colombia's Nevado del Ruiz volcano—often considered to be the most dangerous in the Western Hemisphere—is giving experts cause for concern.

Over the last month, the volcano, which stands west of Bogotá at an elevation of 17,457 feet above sea level, has been spewing ash plumes and steam. This indicates that an eruption could take place at any moment.