The Armero disaster occurred on November 13, 1985, when the Nevado del Ruiz volcano erupted in Colombia. The eruption melted the mountain's glaciers, causing massive mudflows, known as lahars, to sweep down into the town of Armero. This disaster resulted in the destruction of the town and the loss of approximately 25,000 lives. The tragedy highlighted the importance of disaster preparedness and response. Many residents were unaware of the volcanic activity and did not receive timely warnings. The Armero disaster remains one of the deadliest volcanic eruptions in history, serving as a reminder of the potential dangers posed by natural disasters.