The booming earthquake struck about 8:30 local time about 10 miles northeast of Anchorage, at a depth of 21 miles, according to the US Geological Survey. The aftershocks continued after the tsunami alarm was canceled.
"He was very strong when he arrived," said Anchorage Mayor Ethan Berkowitz. "It was very clear that it was something bigger than what we normally live, we live in such an earthquake country … but this was great".
Social media and television videos portrayed scenes of chaos, including students taking shelter beneath the desks as they send texts from their phones, streets that fold under the machines, shopping items falling off the shelves, hospital that hurry to cover and panicked lawyers under the tables as a courtroom cradled from one side to the other.
"It was absolutely terrifying," Kristin Dossett, a resident of Palmer, Alaska, told CNN.
It was the most violent earthquake he experienced in his 37 years in a region where temblors are common, Dossett said. An aftershift moved his plane a foot and a half from the wall.
"He trembled as if I had never heard anything like it before," he said.
"He did not stop, he went on and made himself stronger and stronger, and things fell everywhere, everything out of my beliefs, from my bookstores, from the kitchen cupboard, just broken glass everywhere."
Seismologists predict more aftershocks in the coming days and weeks
Governor Bill Walker has issued a declaration of disaster, according to a post on his Facebook page.
There were no reports of deaths or injuries. The Borough school district of the Kenai Peninsula said that all of his students were safe.
The US Geological Survey reported dozens of aftershocks. The largest, recording 5.7, was located in the city of Anchorage. Seismologists predict many others in the coming days and weeks.
The Anchorage office of emergency management for a period has invited residents to take shelter on the spot.
The municipal Light & Power utility reported that between 7,000 and 10,000 customers were powerless.
"I could say that this was bigger than anything else I had been before, and it would not stop," said Philip Peterson.
Peterson was in a multi-story building in downtown Anchorage as the structure swayed and coffee cups fell from tables and tiles from the ceiling.
"I just jumped under my desk and had to ride it," Peterson said.
Michael West, the state seismologist of Alaska, told CNN that the 7.0 earthquake was felt up to 400 miles outside of Anchorage. West reported that damage reports across the region were starting to arrive at the Alaska Earthquake Information Center.
President Trump tweets: "The federal government will not spare expenses"
The White House has stated via Twitter that President Donald Trump, who is in Argentina, had been informed of the disaster.
Trump tweeted: "For the great people of Alaska, you have been hit hard by a" big ".Please follow the directions of the highly qualified professionals who are there to help you. The federal government will spare no expense. God bless you ALL! "
The former Alaska governor and vice-presidential candidate Sarah Palin tweeted that her home was not intact after the earthquake, but did not develop specific damage.
"[Pray] for Alaska. Our family is intact – the house is not … I guess it's like that for many, many others. So grateful to be safe; pray for our state after the earthquake, "he said on his verified Twitter account.
The Dena's Civic and Convention Center in downtown Anchorage was used as a shelter for those unable to return home.
Two of the city's major hospitals – Alaska Regional and Providence Alaska Medical Center – suffered damage, but emergency rooms were opened, according to hospital officials.
The Anchorage Police Department stated in a statement that it was handling "multiple situations" and reported "major infrastructure damage" throughout the city.
At Ted Stevens International Airport, the Federal Aviation Administration implemented a ground stop for flights. The airport has reopened now after the earthquake.
The FAA said that Ted Stevens' tower was evacuated at some point.
The International Airport Road near Ted Stevens was damaged, said the airport via Twitter, recommending motorists to use extreme caution.
Alaska Airlines operations at Ted Stevens resumed hours later and flights began to arrive and depart from the airport, according to the airline's website.
Blair Braverman said he was staying in a hotel with her husband when the earthquake struck. She grew up in California and was familiar with earthquakes "but this was next-level," he said.
"The bed began to tremble, everything trembled so dramatically," he told CNN.
"My husband crawled across the room and threw himself on me and we crawled into the bathroom together and we waited outside the door and waited for the aftershocks."
"The roof structure has just collapsed," said one. "We can not even get into our studio right now: there were computers flying, cameras spilling".
CNN's Shawn Nottingham, Chuck Johnston, Keith Allen and Matthew Hilk contributed to this relationship.