PAWNEE, Okla. — An earthquake that geologists say appears to be the largest in Oklahoma’s history rattled buildings and woke residents across the state Saturday morning, causing one minor injury and damage to several buildings.

The U.S. Geological Survey (USGS) identified north-central Oklahoma as the epicenter of the 5.6 magnitude quake, which struck at 7:02 a.m, about eight miles from Pawnee, a town of about 2,200 people.

The quake was felt in at least six states, and prompted the temporary shutdown of nearby disposal wells for wastewater produced by oil and gas drilling.

A man protecting his child suffered a head injury when part of a fireplace fell on them, said Pawnee County Emergency Management Director Mark Randell. Randell said the man was treated at a hospital and released.

Bricks fell from buildings in the town of Pawnee, and a furniture store in Enid – about 65 miles away – also reported some structural damage. The Oklahoma governor has called for crews to check bridges and structures for damage after the large temblor.

“We’ve got buildings cracked,” Randell said. “Most of it’s brick and mortar, old buildings from the early 1900s.”

The USGS reported that the initial quake was about 4.1 miles deep, and at least seven aftershocks were felt in the same area over the next four hours.

It was only the fourth quake in Oklahoma to measure over 5 magnitude, the USGS said. Oklahoma has recorded hundreds of smaller earthquakes caused by the injection of wastewater from the oil and gas industry into deep underground disposal wells. 

Oklahoma Corporation Commission, the state agency that oversees drilling, was contacting all disposal well operators in the area of the quake, telling them to shut down their wells, according to OCC Public Information Director Matt Skinner.

Skinner said about 35 operators in the region around the Arbuckle formation — within 500 square miles around the epicenter near Pawnee, in Pawnee County — would be affected. Another 211 square-mile area of concern is in Osage County, Native American lands whose mineral rights fall under federal jurisdiction.

The former record for largest earthquake in Oklahoma’s history was a 5.6 recorded Nov. 5, 2011, near Prague in central Oklahoma.

However, a USGS official is reporting Saturday’s temblor was larger than the Prague earthquake, even though the reported magnitudes were the same as of 9:30 a.m.

“We just determined it’s the largest earthquake, larger than Prague,” said Dan McNamara, a research geophysicist with the USGS, adding data shows it is just a fraction larger even though it is not enough to change the magnitude.

Although the Prague and Pawnee quakes had the same magnitude — 5.6 — McNamara said the Pawnee quake had a slightly larger energy release.

McNamara said they haven’t determined if there was injection well activity in the area, so they can’t confirm if the quake was induced or not.

“It was a 6.6 kilometers depth, so it was down in the deeper basement granitic rocks, not in the upper sediments where oil and gas formations are,” he said. “That’s typical of previous earthquake. Larger earthquakes have been at similar depths.”

Saturday’s quake also was the only quake greater than magnitude 5.5 felt in the conterminous United States in 2016, according to USGS archives. The conterminous United States does not include Alaska nor Hawaii nor quakes off the coasts.

On social media Saturday morning, people reported feeling the quake across Oklahoma and in Kansas, Arkansas, Nebraska, Texas and Missouri.

Oklahoma Gov. Mary Fallin posted on Twitter that crews are checking bridges and structures for damage in the Pawnee area. Fallin also tweeted state officials want structural engineers to look at building safety in the wake of the quake.

Pawnee furniture store owner Lee Wills told The Associated Press that he first thought the earthquake was a thunderstorm.

“Then it just … Everything went crazy after that. It just started shaking,” said Wills, who lives about 2½ miles outside of town. “It rocked my house like a rubber band. Threw stuff off cabinets and out of cabinets, broke glasses.”

Wills said buildings in the downtown area are cracked and sandstone facing on some buildings fell. He described the scene as “a mess.”

Alyson Murrow, who lives in Moore, Oklahoma, posted she woke up to “a picture falling off my wall and doors rattling.”

Char Robinson, of Enid, “felt the shaking, then a large jolt and even more shaking,” she said. “Our pool had waves sloshing around!”

The Stillwater News-Press and The Enid News & Eagle contributed to this report.