A rare earthquake rumbled through Washington D.C., today, shaking windows in the White House and throughout the city but causing no major damage, according to initial news reports.
The relatively small magnitude 3.6 quake originated at 5:04 a.m., about 15 miles away in Rockville, Md. It was the largest quake to strike within 30 miles of the White House, at least since 1974, when the U.S. Geological Survey began tracking D.C. quake activity, according to spokeswoman Amy Vaughn.
ABC News correspondent John Donvan, who lives a mile from the White House, said the quake rattled windows at his home as well.
"I know it's not a cataclysm, but it is a record-setter for D.C.," Donvan said on "Good Morning America" today. "This is not an earthquake zone."
Residents as far away as Fairfax, Va., were surprised by the early morning trembling.
"The first thing that happened, windows just started rattling a real loud rattle and then the floor," Deborah Paige of Stafford, Va., told ABC News' local affiliate WJLA. "I could feel the vibrations on my floor. I live fairly close to Quantico and when they're rehearsing their war games or whatever we can feel their effects. ... It was kind of scary not knowing what it was."
The police station in nearby Montgomery County was swamped with phone calls from mystified residents, according to a report by The Associated Press.
But Michio Kaku, a professor of physics at the City University of New York, told "GMA" that people really shouldn't be so surprised.
"The Northeast is riddled with tiny micro-faults, we forget that," he said. "We think that the ground on our earth is stable. It's not."
Correspondent Donvan's dog may have known something was up five minutes before the quake struck, he said.
"The dog went nuts ... wimpering and complaining," he said. "He went to the door, but then he wouldn't move. Maybe he knew it was coming."
ABC News' Ken Kneeland contributed to this report.