Back-to-back earthquakes, measuring 7.0 and 5.7, have shattered highways and rocked buildings in Alaska, sending people running into the streets and briefly triggering a tsunami warning for islands and coastal areas south of the city.
The U.S. Geological Survey said the first and more powerful quake was centered about 12 kilometres north of Anchorage, Alaska’s largest city, with a population of about 300,000.
People ran from their offices or took cover under desks before the 5.7 aftershock arrived within minutes, followed by a series of smaller quakes.
Chris Riekena was driving his seven-year-old son to school when his car started acting up. As he pulled over, he realized the problem wasn’t his car — it was a huge earthquake.
Mr Riekena turned around to calm his son in the back seat and when he looked forward again, the road ahead of him was sinking into the earth. He pulled his son out of the car as light poles along the road swayed in the air.
By the time the shaking stopped on Friday, the car just in front of his on the freeway was marooned on an island of asphalt with a huge chasm on both sides.
“It was probably a good 30 to 40 seconds of slow-motion disaster,” Mr Riekena said.
“Thankfully I pulled over when I did.
“I’ve walked around the site enough over the last few hours that I’ve replayed that a few times.”
Luckily no tsunami arrived and there were no reports of deaths or serious injuries.
“We just hung onto each other. You couldn’t even stand,” Sheila Bailey, who was working at a high school cafeteria in Palmer, about 45 miles from Anchorage, said.
“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.”
The quake broke store windows, knocked items off shelves, opened cracks in a two-storey building downtown, disrupted electrical service and disabled traffic lights, snarling traffic.
Flights at the airport were suspended for hours after the quake knocked out telephones and forced the evacuation of the control tower. And the 800-mile Alaska oil pipeline was shut down for hours while crews were sent to inspect it for damage.
Jonathan Lettow was waiting with his five-year-old daughter and other children for a school bus near their home in Wasilla, about 40 miles north of Anchorage, when the quake struck. The children got on the ground in a circle while Mr Lettow tried to keep them calm and watched for falling trees.
“It’s one of those things where in your head, you think, ‘OK, it’s going to stop’, and you say that to yourself so many times in your head that finally you think, ‘OK, maybe this isn’t going to stop’,” he said.
Alaska has been hit by a number of powerful quakes over 7.0 in recent decades, including a 7.9 last January southeast of Kodiak Island. But it is rare for a quake this big to strike so close to such a heavily populated area.