In 1991 a volcanic eruption of Mount Pinatubo forced an evacuation and destroyed much of the Clark Air Base, a major United States military facility located 40 miles (60 km) northwest of Manila, which closed shortly thereafter. Most of the sex trade around the base closed at the same time due to the loss of the GI customers. Mayor Alfredo Lim proceeded to crack down on Manila's remaining sex industry, causing many of these businesses to relocate to Angeles City, which borders on the closed base, and was becoming a popular tourist destination especially with former GIs.