The Armero tragedy was a natural disaster resulting from the eruption of the Nevado del Ruiz volcano, which had been dormant for sixty-nine years. On the night of Wednesday, November 13, 1985, the devastating tragedy occurred, causing the disappearance of the municipality of Armero and affecting the departments of Caldas and Tolima. The first signs of volcanic activity were observed in September 1985. The eruption caught nearby towns by surprise, and flows of mud, earth, and debris, the products of volcanic activity, descended the slopes of Nevado at a speed of 60 km/h. Unfortunately, more than 20,000 out of its 29,000 inhabitants perished as Armero was located just under 50 km from the volcano.