A 3.6-magnitude earthquake struck near the Gaithersburg, Maryland, area just after 5 a.m. ET Friday, according to the U.S. Geological Survey.
The center of the quake was about 20 miles northwest of Washington, the USGS said.
"It was really loud, like a plane flying really low. I had never felt anything like it," said Anne Ngunjiri, 30, of Gaithersburg. "I was jolted out of bed. All my neighbors woke up. After it passed, I thought it could be an earthquake, and lay in bed hoping there were no aftershocks."
Judy Rudolph, 64, said she was writing e-mails in bed in Rockville, Maryland, when her house started to shake. "My first reaction was the noise.... I thought it was an explosion," she said. She said she'd never felt anything like it in her 31 years living there.
The last earthquake in Maryland occurred on October 8, 2007, according to the USGS website. It was a 1.7-magnitude quake about 5 miles northwest of Baltimore.