By David DeKok

SCHUYLKILL HAVEN, Pa. (Reuters) - Forensic archaeologists on Friday began excavating a highway embankment in eastern Pennsylvania, looking for more bones believed to be from impoverished victims of the worldwide Spanish flu pandemic in 1918.

The state highway department, known as PennDOT, received reports of bones in what appeared to be an impromptu burial site beneath a broad meadow that had once been the site of a poorhouse, said Bob Rescorla, a PennDOT inspector at the site.

"There were rumors it was a mass grave here," Rescorla said of the burial ground along State Highway 61 in Schuylkill Haven, about 100 miles northwest of Philadelphia.

Historians say the Spanish flu pandemic touched all parts of the world and claimed tens of millions of lives. The flu could kill quickly, sometimes in less than a day.

In Schuylkill County, the Pottsville Republican-Herald newspaper reported that some 17,000 residents were sickened and several thousand died during the pandemic, leaving as many as 3,000 children orphaned.

PennDOT workers had shaved the embankment for a road widening project earlier in the week, Rescorla said, and heavy rains later caused part of the cut to collapse, exposing bones.

Kevin Mock, an archaeologist with PennDOT, told Reuters on Friday he could see leg bones and part of a jaw bone protruding from the embankment. He said there were no coffins.

His research found the connection of the meadow to the Spanish flu pandemic.

Most victims, Mock said, were buried without coffins. He thought it unlikely there could still be active H1N1 flu pathogens - the strain that caused the 1918 pandemic - in the bones or soil given the passage of time and the usual practice of sprinkling lye over buried without coffins.

A team of professors and students from Mercyhurst University in Erie, Pennsylvania, arrived at the site on Friday afternoon along with the Schuylkill County Coroner's Office and cadaver dogs.

The Mercyhurst team set up a sieve for screening soil for bone fragments, and marked visible bone fragments protruding from the embankment with small red flags.

Dr. David Moylan, the Schuylkill County coroner, said the team would not excavate the entire field, but will remove remains near the highway. They will be taken to Mercyhurst University for medical examination and possible DNA extraction.

After that, Moylan said, they will be cremated and buried in a modern cemetery for the unidentified or unclaimed maintained by the county.

(Reporting by David DeKok; Editing by Eric M. Johnson and Sandra Maler)