Buildings in Anchorage, Alaska sustained major damage and sections of highway were destroyed after a pair of earthquakes struck back-to-back Friday morning.

The temblors, which were magnitude 7.0 and 5.7, sent people running out of their workplaces and even triggered a brief tsunami warning for some coastal areas.

Cellphone video posted to Twitter by a student at Colony High School shows teenagers huddled underneath desks for safety as the building rocks back and forth.

"I'm shaking," Alyson Petrie wrote in a follow-up post. "Teachers are keeping us under our tables and telling us that there will be an (aftershock) … I'm in the art classroom and everything is literally destroyed."

The first earthquake hit just north of the city, which is the biggest in the state with a population of about 300,000, shortly before 9:30 a.m. at a depth of 42 kilometres.

There were cracks in buildings and roadways after the shaking stopped. Police Chief Justin Doll told The Associated Press that part of a highway northeast of Anchorage had "completely disappeared."

The quake followed just one day after a 4.2-magnitude earthquake that shook B.C.'s Peace River region – though there are suspicions that one might have been what's known as an "induced" earthquake.

Honn Kao, a researcher with the Geological Survey of Canada, said officials have confirmed there is active hydraulic fracking in the area, and it's possible that's what caused the temblor.

The fracking process involves the high-pressure injection of water into the ground to extract oil or gas, and the industry been under increasing scrutiny for its connection to earthquakes.

"We did observe induced earthquakes related to injection operations in the past. This particular one is very likely to be another case of injection induced earthquakes," Kao said.

"In any area where you have very active activity of hydraulic fracturing and wastewater injection, induced earthquakes are, perhaps, something you cannot avoid."

The B.C. Oil and Gas Commission said fracking operations were immediately shut down as a precaution, but officials have not verified whether there is any direct connection between fracking and the quake.

Residents living in Fort St. John, Dawson Creek and Taylor all reported feeling the tremors on Thursday evening. Fortunately, no damage was recorded.

With files from CTV Vancouver's Allison Hurst and The Associated Press