This Book, produced in the framework of the "community network for disaster reduction" project, aims to build up a culture of safety reduction among young people living in the basins of the Rivers Cañas-Lajas, Pirris-Parrita and Reventazon-Parismina. Its first part is a guide for the setting-up of a community emergency reduction plan based on the experience of 26 communities of the area. The second reviews all phases of an early warning system. (UNEsCO)