Indonesia's rumbling Mount Merapi unleashed a column of hot gas and sent clouds of ash tumbling down its slopes Thursday as 15,000 terrified villagers fled to safety. Some jumped in rivers to escape the searing heat, while others dashed down the volcano or clambered onto the backs of trucks. Indonesia's most dangerous volcano has been venting steam and ash for weeks, but Thursday's 9 a.m. burst was the largest yet, sending billowing, dark gray clouds avalanching 3 1/2 miles down the mountain, said Sugiono, a government vulcanologist. It was one of a series of powerful explosions, some spewing columns of ash 1 mile high.
Some scientists say a May 27 earthquake that killed more than 5,700 people in an area 25 miles south of Merapi may have contributed to the volcano's volatility in recent weeks. The mountain's lava dome has swelled, raising concerns that it could suddenly collapse, sending scalding clouds of fast-moving gas, lava and rocks into still-populated areas.
Yousana Siagian, a senior official at the government's Vulcanology and Disaster Mitigation Center, said a shallow 4.2-magnitude aftershock Thursday, 17 miles south of the peak, may have speeded things along.
Merapi's last deadly eruption was in 1994, when it sent out a searing gas cloud that burned 60 people to death. About 1,300 people were killed when it erupted in 1930. Authorities said that another major, deadly eruption would severely strain ongoing earthquake relief operations in nearby Bantul and Klaten districts. More than a half-million people were displaced in last month's temblor, many living in makeshift shelters with no toilets or running water.