On 15 June 1991, Angeles was affected by the cataclysmic eruption of nearby Mount Pinatubo, with up to 60,000 people being evacuated from the city. It was the second-largest volcanic eruption of the twentieth century and, by far, the largest eruption to affect a densely populated area. The province of Pampanga, Clark specifically, were badly hit and the agricultural lands, as well as other businesses, were covered by tons of lahar. There were no casualties reported inside Clark two days from the initial eruption because the 18,000 personnel and their families were transported to Guam and the Subic Naval Base in Zambales.