In these lines I would like to tell about one of the first disasters that I have lived while I was in Santiago de Chile. The major hazards to which Chile is traditionally vulnerable are earthquakes, Tsunamis, and floods. But back in 1993 a climatic phenomenon was triggered that jeopardized an extensive region of the territory of the gorge of Macul.  Gorge of Macul is on the Southeast side of the city of Santiago in a densely populated zone.  The event originated serious problems, being those of greater gravity the happened ones in the gorges of the Metropolitan region, especially in the gorge of Macul. 

   May second and third of 1993 the Central zone of Chile was affected by a weather system that appeared with intense liquid precipitations and elevated temperatures that were usual at that time of the year.  Indeed, the isotherm of 0ºC rose over 3900 meters above the sea level, while at the same time the surface of the river basin was also rose as a result of receiving liquid precipitation. This phenomenon made the snow of the mountains melt and slide into the rocky valley.  All the authors who studied this phenomenon agree that there was no sliding of great masses likely to block the channel, therefore the alluvium process was due to the great amount of fallen water and to the superficial contribution of the high zones ?but of hills?, this produced a diminution of the infiltration and saturation of grounds, facilitating the local erosion. 

   The flowing material was increasing in amount, dragging along blocks and rocks that were in the river basin, forming a highly viscous mass of blocks and mud that slipped down slopes, with tributary channels becoming incorporated into the main channel and making a significant contribution.  Witnesses of the phenomenon indicated that the alluvium appeared as two waves separated by an interval of 10 minutes. 

   The community mobilization was amazing.  ONEMI, the National Emergency Office, declared disaster area, and Police, Firefighter, Medial personnel, College Students, and Neighbors were organized to contribute to the rescue and recovery procedures.  During the first hours of the emergency the principal activities consisted of rescue of the people who were trapped under collapsed houses.  The police and firefighters fought against mud, debris, rain and cold.  Then students and neighbors started to remove the mud from houses while rescue teams began finding casualties under the sludge.  The recovery efforts took several weeks. 

   The alluvium unloaded on a population sector in the community of Florida.  The alluvium did not respect social status, ages, sex, or religion, but as is always the case in developing countries, the poorest people were the most affected.  The disaster left a balance of 26 fatal victims and 8 missing people.  The material damages included 257 destroyed houses, 36 houses damaged by 30% to 70%, and 171 houses damaged up to 30%.  The State had almost 2000 victims in shelters and 5000 victims outside shelters.  The damage of houses alone was estimated to reach $1.5 million, to which the expenses of the emergency must still be added. 

References:
http://www.u-noticias.cl/marzo/aluviones.htm
http://www.quepasa.cl/sitios/especiales/aniversario/t_modernos/desastres2.htm