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PHILADELPHIA (CBS/AP) – 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 U.S. Geological Survey said the first and more powerful quake was centered about 7 miles (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.

Aaron Poole | Credit: CBS3

Experts say the aftershocks will continue. Over the next 24 hours, there could be between 10 and 1,000 aftershocks of a magnitude three or greater. So the concern still lingers for people there and a South Jersey father whose son just moved to Alaska.

“They were pretty much in the epicenter. They live in Eagle River,” said Al and Cathy Poole on Friday night. [It was] 12:30 our time and basically he said they are having an earthquake.”

We were able to get ahold of their son Aaron, who says Alaska has a lot of earthquakes but this one was different.

“At first we started giggling and then the giggling went to instant fear people getting underneath desks and into doorways. It lasted somewhere between 25 and 40 seconds. It was pretty long in the world of earthquakes. This house has at least 150,000 in structural damage to it,” said Aaron Poole who lives in Anchorage Alaska.

Alaska was the site of the most powerful earthquake ever recorded in the U.S. The 9.2-magnitude quake on March 27, 1964, was centered about 75 miles (120 kilometers) east of Anchorage. It and the tsunami it triggered claimed about 130 lives.

The state averages 40,000 earthquakes a year, with more large quakes than the 49 other states combined. Southern Alaska has a high risk of earthquakes because the Earth’s plates slide past each other under the region.

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.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)