Mt. Pinatubo is a stratovolcano in the Philippines. June 15, 1991, it erupted, resulting in the second-largest eruption of the 20th century. The ash plume height reaching more than 40 km (28 mi) high and ejecting more than 10 km3 of magma, classifying it as plinian/ultra plinian eruption style and VEI 6 in eruption size.
A complicating factor in the dispersal of ash was at the same time as the eruption, Typhoon Yunna channeled the ash from the usual dispersal out to the ocean toward the island of Luzon. This combination gave rise to wet ash, increasing loading on structures with a large proportion of the 847 death toll due to roof collapse.
1991 Mt. Pinatubo eruption caused widespread impacts across societal, economic and environmental areas. Pyroclastic flows, lahars as well as the ashfall hazard all resulted in damage and casualties. The eruption cost $700 million in damage, $100 million of which was damage to 16 aircraft flying at the time of the eruption and $250 million in property with the rest a combination of agriculture, forestry and land.