An earthquake centered in northern Oklahoma Saturday morning that was felt across the Great Plains has been upgraded to the largest in the state's history.

According to initial U.S. Geological Survey map, a 5.6 magnitude earthquake was reported just northwest of Pawnee, Oklahoma at 7:02 a.m., equaled the largest earthquake to ever hit the state.

On Wednesday, the USGS upgraded the temblor to a 5.8-magnitude, making it the single largest ever in Oklahoma.

"The magnitude revision is based on further in-depth analysis of seismic recordings," reads a post on the USGS website. "Changes in estimated magnitude for an earthquake are common in the hours-to-days following the event, as more data are analyzed in greater detail than is possible in the first minutes after the earthquake occurs."

The quake prompted authorities in the town of Pawnee, near the quake's center, to dispatch officers to check key facilities, such as the local water plant.

Pawnee County Emergency Management reported that at least one building collapsed, according to local media reports.

Police radio traffic reported that the quake had apparently caused several structural fires, including one barn, near the town of around 2,000 people.

There were no immediate reports of injuries.

The magnitude-5.6 equaled a quake that struck the town of Prague, in Lincoln County, in November 2011, according to the USGS. That quake was also upgraded Wednesday to a 5.7.

“While the difference in size between the two events is less than 0.1 magnitude units, rounding magnitudes to one decimal place means that the magnitude of the Prague earthquake is Mw 5.7, and the Pawnee earthquake is Mw 5.8," said USGS research geophysicist Gavin Hayes.

There have been just four earthquakes of 5.0 magnitude or greater in Oklahoma's history, according to a Tulsa World report.

The USGS told News 8 people reported feeling Saturday's quake from North Texas to North Dakota.

Multiple aftershocks, as powerful as a 3.6 magnitude, hit the same area near Pawnee in the hour following the initial temblor, the USGS reported.

Social media erupted with people saying they felt the record-tying tremor. Stories of shaking houses and swaying high-rises poured in from areas hundreds of miles apart. What did you feel? Click and share with WFAA.

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The USGS said it will work to determine whether or not Saturday's quake was related to fracking. From the USGS:

Without studying the specifics of the wastewater injection and oil and gas production in this area, the USGS cannot currently conclude whether or not this particular earthquake was caused by industrial-related, human activities. However, we do know that many earthquakes in Oklahoma have been triggered by wastewater fluid injection.

Contributing: Doug Stanglin, USA TODAY