A construction worker unearthed a mass grave last week in Pennsylvania while working on private property along Route 61 in Schuylkill Haven, a borough of about 5,000, situated 89 miles northwest of Philadelphia.

Local historians believe it was at that location, in 1918, that almost 1,600 county residents were wiped out by Spanish influenza and the remains could belong to those victims, according to Newser.

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

The property where the mass grave was found belongs to Joan Bachman and her husband, who heard rumors about it being the resting place of previous residents when they bought the land in 1997.

"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."

Because of the rate so many people were dying at, historians say it wasn't uncommon for people to just be buried in a field with no markers, reported WNEP. This, in turn, allowed such graves to remain hidden in plain sight.

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

A local coroner revealed that the bones found are intact enough to be identifiable with the naked eye and include a tibia, femur and jaw bone. A forensic archeology team from the Mercyhurst University in Erie, Pa., was sent to the site to run tests on the bones, including one to determine if there is any DNA they can match with those bones to find out who they belonged to, according to PIX 11.

It could take weeks before the results of the forensic tests come in and, once they are, county officials plan to hold a proper burial for the remains.