Imelda Kusmawati's husband grabbed their two children and ran from the house when the ground reared up beneath them, cracking roads and collapsing nearby buildings in seconds. The powerful earthquake — the latest in a string of natural disasters to hit Indonesia — killed at least 52 people and injured hundreds.
• Monitor the situation in FOXNews.com's Natural Disasters Center.
"My house is on the brink of collapse," said Kusmawati, 28, one of tens of thousands sleeping in tents or under the stars instead of returning indoors after Tuesday's quake. "I am still traumatized and worried about aftershocks," she said as her son and daughter huddled close to her.
The 6.3-magnitude quake struck on Sumatra island just before 11 a.m. and was felt as far away as neighboring Malaysia and Singapore, where some tall buildings were evacuated. Two hours later, a 6.1 aftershock rattled the region.
In Solok, a bustling town close to the epicenter, two children were killed when a building collapsed on the school playground, said police spokesman Supriadi, who like many Indonesians uses only one name. Three members of one family were burned alive when their collapsed home burst into flames.
Indonesia, which straddles one of the world's most seismically violent zones, was hardest hit by the 2004 Asian tsunami that killed 160,000 people on Sumatra's northern tip. Since then, two other deadly quakes have occurred, as well as landslides, floods and volcanic eruptions.
Dozens of buildings were destroyed and hundreds others damaged by Tuesday's quake, according to local police chief Lt. Col. Budi Sarwono. TV footage showed a flattened three-story home and wide cracks in the road.
At least 52 people were killed in Tuesday's quake, Cabinet Secretary Sudi Silalahi said Wednesday, lowering the death toll from 70. He said some victims had been counted twice. Officials said some 250 people were injured.
"Women were crying out in terror," said Alpion, a welder who ran to higher ground, fearing a tsunami that never came. "We all just fled as quickly as we could."
Patients poured into hospitals, many with broken bones and cuts, but most were treated outside because of fears of more quakes. Scores were laid out on cots on a soccer field, where they were attached to intravenous drips and given emergency care.
"So far we have recovered 19 bodies and hundreds of injured people," Sarwono said in Solok. "The two hospitals are overwhelmed."
A witness in the town of Payahkumbuh said several shops in the main street had collapsed and police and soldiers were digging for survivors. Electricity remained cut in parts of the nearby seaside town of Padang as darkness fell hours later.
Local government spokesman Hasrul Piliang said the number of dead "would likely rise" because tallies from remote areas were still being collected and there were reports of people trapped under debris.
The U.S. Geological Survey said the tremor struck 20 miles below Solok. It was felt in Singapore, 265 miles away, forcing the evacuation of several older office buildings, TV station Channel NewsAsia reported.
In Malaysia's southern coastal city of Johor, citizens fled offices, buildings and shopping centers, witnesses said.
U.S. earthquake expert Kerry Sieh was in Padang on a research trip when the quake struck. He fled his fourth-story hotel room like other guests, stopping only to unplug his laptop.
"I was pretty scared," he said, adding that the fault that spawned the quake was known as the Great Sumatran, which last ruptured in 1945. "I now know why people have a hard time remembering how long earthquakes last."
Indonesia, the world's largest archipelago, is prone to seismic upheaval because of its location on the so-called Pacific "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin.
In addition to the 2004 tsunami, an earthquake killed nearly 5,000 on Java island last year.
Tuesday's quake was about 660 miles west of Jakarta.
Visit FOXNews.com's Natural Disasters Center for complete coverage.