Mount Pinatubo, a 1,760-m (5,770-ft) volcano in the northern Philippines, erupted in 1991 after being dormant for 600 years.

Another eruption in 1992 again caused widespread devastation. From June 12 to June 16, 1991, the volcano erupted four times, releasing more than 20 million tons of debris into the stratosphere.

The accompanying thick volcanic mudflow, or lahar, killed 800 people, made about 50,000 people homeless, affected 87,000 ha (214,980 acres) of rice farmland, and destroyed numerous fishponds, river valleys, bridges, and villages.

Volcanic ash silted river valleys, causing extensive flooding that devastated six provinces in the fertile Central Plain.

The silting of river channels and trapping of rainwater in an area of 300 km2 (116 mi2) formed Lake Pinatubo, now 10 m (33 ft) deep. Permanently submerged in this lake are 500 structures, including houses, churches, and schools. The 1991 eruptions are believed to be the major reason why temperatures dropped globally in 1993 and the largest hole yet recorded in the ozone layer occurred over the South Pole.

The volcano erupted again on Sept. 21, 1992, destroying some 10,000 homes and disrupting the lives of nearly one million people. Millions of dollars from the government of the Philippines and international aid were poured into cleaning efforts and relief for victims of the disaster. Attempts to replant the lahar-covered fields with rice and cassava met with very limited success. In 2001 a lake in the volcano’s crater threatened to flood the surrounding area. In September of that year a hastily dug canal lessened the danger of flooding but did not eliminate it.

Below you can watch a video of the Mount Pinatubo eruption and its consequences: