Thousands of people fled their homes Sunday as a volcano, long believed to be inactive, erupted in North Sumatra province. The last time it had been heard from was the 17th century. According to Indonesia’s volcanology and geology agency, it began spewing ash in the wee hours of Sunday morning, but no one is sure what to expect, though a large-scale explosion of lava now seems unlikely. "We don't know the character of this volcano because it's been dormant for so long," the head of the agency said. There are no reports of casualties or injuries so far.