Investigators in Bradford County in northeast Pennsylvania say that a tornado caused the damage in Franklin Township.
The National Weather Service survey conducted on Thursday confirmed damage consistent with an EF-2 tornado, with estimated maximum winds of 130 miles per hour (201 km/h).
There are no reports of injuries.
The storm struck the Wilkes-Barre Township shopping plaza late Wednesday night.
The storm came through around 10 p.m. Wednesday, following a tornado warning the National Weather Service issued.
Emergency crews from across the region have also been called in, with the American Red Cross on the scene assisting the first responders.
Strong storms, apparent tornadoes flip cars and trigger building collapses in Pennsylvania
Don Brominski, spokesman for UGI Utilities, said the storm damaged some of the utility's gas meters but that the leaks had been stopped. They asked drivers to avoid the area to allow emergency personnel access to the shopping plaza.
Pictures and video posted on social media show shattered storefronts and major damage to numerous businesses including a Panera Bread restaurant. Wednesday, and touched down near Mundy Street and Highland Park Boulevard near the Wyoming Valley Mall.
Bruno Isles, a Panera employee, told the (Wilkes-Barre) Times Leader he was washing dishes in the back of the restaurant at the time.
A possible tornado left a path of damage in northeastern Pennsylvania.
"The doors were busting open", Frie said. "We had tables and chairs flying through the windows".
Township Police Chief Ron Smith said the six injured people suffered only minor wounds and were not hospitalized.