US and Philippine volcanologists install seismic sensors near the crater of Mount Pinatubo volcano in 1991. The volcanic eruption was one of the biggest in history. Ten years after the volcanic eruption and the departure of the Americans the base now offers duty free shops, restaurants, garment and also electronic factories. Although Mount Pinatubo wreck havoc in Pampanga Province, the closure of Clark Air Base was devastating to the commercial business in the area.