The 1985 eruption of Colombia's Nevado del Ruiz volcano produced the deadliest lahars (volcanic mudflows) in recorded history. A relatively moderate explosive eruption melted parts of the summit icecap and sent lahars down four major drainages. The town of Armero, shown here, was destroyed by a lahar that had traveled 74 km east of the summit and exited a narrow canyon above the town in a 40-m-high wave. Three-quarters of the 28,000 inhabitants of Armero were killed because officials and residents were not prepared for the danger the volcano posed.

Copyrighted photo by Katia and Maurice Krafft, 1985.

Copyrighted image used with permission. All Rights Reserved. Contact photographer for any usage requests.

Nevado del Ruiz