SCHUYLKILL HAVEN, Penn. — A construction crew unearthed a 100-year-old mystery when they dug up a mass grave in Pennsylvania while working on a roadway, WNEP reports.

The historic find was made along Route 61 in Schuylkill Haven, a borough of about 5,000 situated 89 miles northwest of Philadelphia.

It was there in 1918 that almost 1,600 county residents died from Spanish influenza and historians believe the remains could belong to those victims.

"There was genuine panic," Tom Drogalis, of the Schuylkill County Historical Society, told WNEP about the outbreak nearly 100 years ago. "Everything closed -- schools, hospitals, the only thing left open were drug stores."

Because so many people were dying so fast, it wasn't uncommon for the deceased to be buried in a field with no markers, WNEP reports.

"They did, indeed have several mass potters' graves, if you will, at the time," Drogalis said. "And one of them was identified as being in Schuylkill Haven."

Crews are unearthing the bones and a forensics archaeology team from Mercyhurst University with run tests in an attempt to identify who those remains belonged to in life.

Among the remains are body parts easily identified just by looking at them, such as a tibia, femur and a jaw bone, Schuylkill County Deputy coroner Joseph Pothering told WNEP.

The property on which the mass grave was found belongs to Joan Bachman and her husband, who heard rumors when they bought the land in 1997 hat it may have been the final resting place of residents before her.

"They told us it possibly could have been a burial ground from many, many years ago, 100 years ago," she said of the rumors. "So evidently it is."

It could take weeks before the results are in and scientists have a clearer picture about who went into the grave. County officials said they plan to hold a proper burial for the remains when the research is complete.