PADANG – The capital of West Sumatra was reeling in chaos late Thursday afternoon following a devastating 6.8 magnitude aftershock, one of many tremors to hit Indonesia in two days.

Humanitarian agency World Vision is conducting assessments of the damage and needs of survivors, says Enda Balina, the agency’s emergency communications officer in Indonesia.

“Many buildings have collapsed, including a hospital,” she says. “We’re afraid many people are trapped inside the rubble.”

Balina also indicated Padang’s roads were congested with people fleeing the area, and the city’s airport was overwhelmed with crowds. Her comments made by telephone were barely audible under the roar of sirens, as police and emergency personnel were responding to the disaster. She arrived this afternoon with a World Vision assessment team.

Thursday’s quake followed a 7.6 magnitude jolt that Indonesia officials estimate has killed at least 400. The death toll from that earthquake is expected to rise, according to Indonesian officials.

Balina is a disaster response veteran, and worked for more than a year following the devastating Asia tsunami in December of 2004.

World Vision began working in Indonesia in 1961 and today has nearly 90,000 sponsored children in programs in several of the island nation’s communities.