Residents of nearby Angeles panicked at the roar of the initial blast, and thousands of people packed roads after a huge gray-greenish mushroom cloud burst from the volcano and turned day to night.; At a refugee center in Olongapo, 35 miles southwest of the volcano, survivors told of the sky growing dark, then of hearing a tremendous explosion followed by a rain of ash.; "Stones as big as my head were falling down from the mountains," said Rolly Soria, 18.; "There was panic everywhere," said Manuel Romualdo, who fled with his wife, five children, a cat and a dog. "Children were crying. We had to grab whatever we could."; Scientists warned of more, possibly larger eruptions from the 4,795-foot volcano, which was dormant for six centuries until it began spewing steam in April.; "This could only be the beginning," said Raymundo Punongbayan, director of the Philippine Institute of Volcanology and Seismology.; Tens miles to the east, hundreds of Americans fled Clark Air Base, home to 15,000 American military personnel and their families. Most of the base's residents had been evacuated Monday.; Clark did not appear threatened by volcanic flow, and there were no immediate reports of casualties.; Seismologists said searing gas, ash and molten rock raced at great speed down the mountain's western and northern slopes and into the Marella, Maraunot and O'Donnell rivers.; About 3,000 Aeta tribesman, descendants of the original inhabitants of the Philippines, fled the slopes of Mount Pinatubo.; People scampered for safety with their belongings and livestock over roads slippery with ash fall. Refugees wore cardboard boxes to protect themselves from the ash.; "They were stunned by the eruption," reporter Bert Basa said by telephone from Angeles. "Their faces turned ashen, and it looked like their hair was standing on end."; Ash was so thick in the air that at noon, motorists were driving with their headlights on and wipers operating to clear the windshields of volcanic debris. Bits of ash wafted across the roads as if along a windy beach.; A photographer who circled the volcano in an airplane said an aerial gunnery range at Clark was covered with ash, as were mountains in the Zambales range, normally lush, green tropical peaks that now looked like the Alps in winter.; Today's eruptions began at 8:40 a.m. with a tremendous blast that sent forth a mushroom cloud. It was followed by a second explosion a few minutes later and a third, smaller blast at 11:49 a.m.; The huge plume 12 1/2 miles high could be seen in Manila, 60 miles to the south, and reporters at the scene said it blocked out the sun. The cloud drifted westward into the South China Sea.; Seismologists said the volcano had plenty of built-up magma and even more severe eruptions could come later.; "The crisis has not ended," said Punongbayan, of the Philippine Institute of Vulcanology and Seismology. "We have signs that the volcano is preparing for another one."; Punongbayan warned people within a 12-mile radius of Pinatubo to flee.; "The smoke is very thick like a dark mushroom in the sky," television reporter Gus Abelgas said in a broadcast from Botolan, near the volcano's western slopes. "It's just like what we saw in Hiroshima."; President Corazon Aquino visited refugee centers near Angeles briefly before returning to Manila for independence day celebrations.; Moments after the first explosion, sirens wailed at Clark Air Base, and 600 of the 1,500 Americans remaining there fled eastward to safety. Air Force spokesman Lt. Col. Ron Rand said 900 Americans, mostly security personnel, remained at the 130,000-acre base.; Clark is one of the biggest U.S. bases overseas. Punongbayan said Tuesday that the site was in the path of the volcanic flow from Mount Pinatubo during its last major eruption, in 1380.; The Pentagon, which is trying to negotiate a new contract with Manila for the base, said it can work around the temporary loss of Clark.; The Americans who fled Clark with a few belongings on Monday moved in with sailors and their families at Subic Bay naval base, 50 miles to the southwest.; Although the Air Force left Clark, Philippine authorities have not ordered a general evacuation of Angeles, a city of more than 300,000 people adjacent to the base.; When Mount Pinatubo erupted today, church bells pealed to sound the alarm and many people froze in their tracks with fear. Many scampered for safety indoors.; About 19,000 Filipinos had earlier been evacuated from three provinces near the volcano's slopes and were housed in about 25 makeshift evacuation centers outside the projected danger zone.; Officials said more were evacuated after today's eruption but they could provide no new figures.; In the Sapang Bato area of Angeles, the city district nearest the volcano, just 2,000 of 13,000 residents had been evacuated as of Monday, officials said.; Reporters visiting the village today found it abandoned except for a few chickens and cattle. Houses were padlocked, but the explosion had shattered some windows.; Private jeep and bus companies were ordered to the area today to pick up stragglers. About 10 people in Moraza, a village on the western slope, were refusing to leave, relief officials said. They told rescuers that they would not leave their livestock and if the animals die, "we will die with them."; On April 2, Pinatubo produced a small hydrothermal explosion caused by underground water meeting hot rocks deep inside.; On June 3, the volcano spewed ash in a mild eruption. That same day, 4,452-foot Mount Unzen in Japan erupted with an explosion of superheated gas, ashes and rocks that killed 38 people.; A larger flow days later razed dozens of houses.; Experts say there is apparently no connection between Unzen and Pinatubo.; There are about 21 active and 200 dormant volcanoes in the Philippines. The last major eruption was the Taal volcano, about 50 miles south of Manila, in 1965. That explosion killed about 200 people.
Survivors of the Mount Pinatubo eruption relocated to a refugee camp near Olongapo, told a tale of panic and flight. The eruption began with a great gray-greenish mushroom cloud that turned day into night. A rain of ash followed. Refugees even used cardboard boxes in an attempt to protect themselves from ash. Clouds of volcanic ash drifted towards the South China Sea. Seismologists warned that the crisis may not be over. They believe that the volcano has plenty of built-up magma and that more severe eruptions could follow. One news reporter likened the huge eruption as being similar to a nuclear explosion.