Back-to-back earthquakes measuring 7.0 and 5.7 shattered highways and rocked buildings Friday in Anchorage and the surrounding area, sending people running into the streets and briefly triggering a tsunami warning for islands and coastal areas south of the city.
No tsunami arrived and there were no immediate reports of deaths or serious injuries.
The US Geological Survey said the first and more powerful quake was centered about 12 kilometers north of Anchorage, Alaska's largest city, with a population of about 300,000. People ran from their offices or took cover under desks. The 5.7 aftershock arrived within minutes, followed by a series of smaller quakes.
"We just hung onto each other. You couldn't even stand," said Sheila Bailey, who was working at a high school cafeteria in Palmer when the quake struck. "It sounded and felt like the school was breaking apart."
Anchorage Police Chief Justin Doll said he had been told that parts of Glenn Highway, a scenic route that runs northeast out of the city past farms, mountains and glaciers, had "completely disappeared."