The ground shook hard along Indonesia's Flores Island early Saturday morning. A magnitude 7.7 earthquake struck off the coast at 5:58 a.m. local time. It killed at least 47 people and damaged buildings across East Nusa Tenggara province.
A shallow and powerful tremor
The United States Geological Survey placed the epicenter about 68 kilometers (42 miles) north-northwest of the city of Ende. The quake struck at a depth of 10 kilometers (6.2 miles). Shallow quakes of this kind tend to cause more damage than deep ones.
The tremor damaged homes, churches, and public buildings across the region. Photos from Ruteng, in the Manggarai district, showed houses with collapsed walls and piles of rubble. Hospitals reported treating people injured by falling debris.
Tsunami warning issued and lifted
Indonesia's Agency for Meteorology, Climatology, and Geophysics issued a tsunami warning right after the quake. The alert covered East Nusa Tenggara, West Nusa Tenggara, South Sulawesi, and Southeast Sulawesi. Officials told coastal residents to move inland or to higher ground.
Hours later, the agency declared the warning over. No large waves were reported along the coast.
Aftershocks and rescue work
At least ten aftershocks followed the main quake, according to the USGS. The shaking kept many residents outdoors through the day.
Rescue teams moved into damaged towns to search for survivors. Officials said the death toll could rise as workers reached remote villages. The quake is one of the strongest recorded anywhere in the world this year. It struck along the Pacific Ring of Fire, a zone of heavy seismic activity that runs through Indonesia.
Indonesia sits on several tectonic plates and experiences thousands of earthquakes every year. Since the 2004 Indian Ocean tsunami, the country has built a network of early warning systems and practiced evacuation drills in coastal areas.