MINERAL // The most powerful earthquake to strike the East Coast of the US in 67 years shook buildings and rattled nerves from Georgia to Maine yesterday.
Frightened office workers poured on to the streets of New York, while parts of the White House, Capitol and Pentagon were evacuated.
There were no deaths or serious injuries.
The National Cathedral's central tower and three of its four corner spires were damaged but advisers told President Barack Obama there was no major damage to the nation's infrastructure, including airports and nuclear facilities.
The US Geological Survey said the quake registered magnitude 5.8 and was centred 144 kilometres south-west of Washington.
It was mild by West Coast standards but the east of the country is not used to quakes - and this one briefly raised fears of a terror attack less than three weeks before the 10th anniversary of September 11.
"I thought I was having a heart attack and I saw everybody running," said Adrian Ollivierre, an accountant who was in his office on the 60th floor of the Empire State Building when the shaking began.
"What it is, is the paranoia from 9/11 and that's why I'm still out here - I'm not playing with my life."
Two nuclear reactors at the North Anna Power Station in Louisa County, Virginia, the same county as the epicentre, were automatically taken offline by safety systems, said Roger Hannah, a spokesman for the US Nuclear Regulatory Commission.
At the Pentagon, a low rumbling built until the building was shaking and people ran into the corridors. The shaking continued, to shouts of "evacuate! evacuate!"
The main damage to the building, the largest single workspace for the federal government, came from a broken water pipe.
The Park Service closed all monuments and memorials on the National Mall. Engineers found a crack near the top of the Washington Monument. A park Service spokesman Bill Line said on Tuesday that structural engineers found the crack where the 169-metre landmark narrows considerably.
Many non-essential workers in Washington were sent home.
The Capitol reopened by late afternoon for people to retrieve their things.
The National Cathedral said cracks appeared in the flying buttresses around the apse at one end.
"Everyone here is safe," the cathedral's official Twitter feed read. "Please pray for the cathedral as there has been some damage."
In lower Manhattan, the 26-storey federal courthouse - blocks from the site of the September 11 attacks - began swaying, with hundreds of people streaming out.
The New York police commissioner, Raymond Kelly, was in a meeting with top deputies planning security for the upcoming anniversary when the shaking began.
People in the Empire State Building poured into the streets, some having descended dozens of flights of stairs. "I thought we'd been hit by an airplane," said worker Marty Wiesner.
New York district attorney, Cyrus R Vance, was starting a news conference about the dismissal of the sexual assault case against Dominique Strauss-Kahn, the former head of the International Monetary Fund, when the shaking began.
Reporters and aides began rushing out the door until it became clear it was subsiding.
On Wall Street, the floor of the New York Stock Exchange did not shake, officials said, but the Dow Jones industrial average sank 60 points soon after the quake struck.
The Dow began rising again 30 minutes later and finished the day up 322 points.
Shaking was felt as far south as Charleston, South Carolina, as far north as Maine and as far west as Cincinnati and Atlanta.
It was also felt on Martha's Vineyard, off the coast of Massachusetts, where Mr Obama is on holiday - he was starting a round of golf when the quake struck at 1.51pm.
He led a conference call about the quake yesterday afternoon with top officials such as his homeland security secretary, national security adviser and administrator of the Federal Emergency Management Agency. Around Mineral, Virginia, a small town close to the epicentre, people milled around on their lawns, pavements and car parks, still wary of re-entering buildings.
All over town, masonry was crumpled and stores had shelved contents strewn on the floor. Several display windows at businesses were broken.
Carmen Bonano, who has a one-year-old granddaughter, sat on the porch of her family's house, its twin brick chimneys destroyed. Her voice still quavered with fear.
"The fridge came down off the wall and things started falling," she said.
"I just pushed the refrigerator out of the way, grabbed the baby and ran."
By West Coast standards, this quake was mild. Since 1900, there have been 50 quakes of magnitude 5.8 or greater in California alone.
The quake was 3.7 miles beneath the surface but scientists have said they may never be able to map the exact fault.