(WHTM) — With an outbreak of severe weather that hit the Midstate on Sunday, a few tornadoes touched down in the Keystone State. All of these tornadoes were categorized as being weak tornadoes, within the EF0 and EF1 range.

But what was the strongest tornado to hit Pennsylvania? You have to go back nearly 40 years ago to 1985.

According to the National Weather Service out of State College, the strongest tornado was an F5 that struck back on May 31, 1985. This was during a larger severe weather outbreak that impacted Ohio, New York, and Pennsylvania.

“This was an unprecedented event for this part of the country in terms of the magnitude of the tornado outbreak,” Penn State tornado researcher Paul Markowski said. “There were approximately 90 people killed, roughly 65 of them were in the state of Pennsylvania alone, which in a few hours we equaled the death toll of the previous half-century of tornado fatalities in the state. This was a high-end outbreak by any objective measure.”

The F5 that impacted Pennsylvania actually began in Ohio and tracked 47 miles into the town of Wheatland, Pennsylvania. The town is just two miles southwest of the town of Mercer. The tornado killed 18 people across its path and injured over 300.

The National Weather Service says over 100 buildings were leveled, and several industrial facilities were severely damaged.  About 59 other Pennsylvania homes were also damaged due to this violent tornado. 

This F5 is the only tornado on record to strike the state. During the outbreak, over 10 tornadoes struck Pennsylvania. This outbreak is one of the deadliest on record, with 2 other events being deadlier.

“Two days since then have had more tornado deaths, and those were both in 2011: the April 2011 Mississippi and Alabama events and then the Joplin tornado the same year,” Markowski said. “Those are the only two events since May 31, 1985, that have been deadlier from a tornado standpoint.”