HAITI -- The most powerful aftershock yet struck Haiti on Wednesday, shaking more rubble from damaged buildings and sending screaming people running into the streets eight days after the country's capital was devastated by an apocalyptic quake.
The aftershock was initially measured at 6.1 magnitude but later revised to 5.9, according to the U.S. Geological Survey. It was the largest of more than 40 significant aftershocks that have followed the Jan. 12 quake. The extent of additional damage or injuries was not immediately clear.
Wails of terror rose from frightened survivors as the earth shuddered at 6:03 a.m. U.S. soldiers and tent city refugees alike raced for open ground, and clouds of dust rose in the capital.
The Geological Survey reported Wednesday's quake was centered about 35 miles west-southwest of Port-au-Prince and 6.2 miles below the surface - a little further from the capital than last week's epicenter was.
"It kind of felt like standing on a board on top of a ball," said U.S. Army Staff Sgt. Steven Payne. The 27-year-old from Jolo, West Virginia was preparing to hand out food to refugees in a tent camp of 25,000 quake victims when the aftershock hit.
Last week's magnitude-7 quake killed an estimated 200,000 people in Haiti, left 250,000 injured and made 1.5 million homeless, according to the European Union Commission.
The strong aftershock prompted Anold Fleurigene, 28, to grab his wife and three children and head to the city bus station. His house was destroyed in the first quake and his sister and brother killed.
"I've seen the situation here, and I want to get out," he said.
A massive international aid effort has been struggling with logistical problems, and many Haitians are still desperate for food and water.
Still, search-and-rescue teams have emerged from the ruins with some improbable success stories - including the rescue of 69-year-old ardent Roman Catholic who said she prayed constantly during her week under the rubble.
Ena Zizi had been at a church meeting at the residence of Haiti's Roman Catholic archbishop when the Jan. 12 quake struck, trapping her in debris. On Tuesday, she was rescued by a Mexican disaster team.
Zizi said after the quake, she spoke back and forth with a vicar who also was trapped. But he fell silent after a few days, and she spent the rest of the time praying and waiting.
Doctors who examined Zizi on Tuesday said she was dehydrated and had a dislocated hip and a broken leg.
Two women were pulled from a destroyed university building. And near midnight Tuesday, a smiling and singing 26-year-old Lozama Hotteline was carried to safety from a collapsed store in the Petionville neighborhood by the French aid group Rescuers Without Borders.