The remains of at least twelve people were discovered underground next to Washington Square Park on Tuesday by a crew of Department of Design and Construction workers who unearthed a white-walled burial vault.

Situated near the intersection of Waverly Place just past the park's eastern edge, the vault likely dates back to the 19th century—a contemporary of the water mains DDC workers were upgrading when they made the discovery. "We had no idea about the vault," DDC spokeswoman Shavone Williams told us this morning. "If we'd known about it, we wouldn't have dug there."

"It doesn’t creep me as much as it just intrigues me,” one neighbor told CBS. “If it were more recent it might be creepy; if it were from, like, the 1980s." Fair enough.

"We are always sensitive, knowing that there is so much rich history around," Williams added. In Washington Square Park, that history is already understood to be decidedly morbid—from 1797 to 1826 the eastern end of the park was a potter's field or, as the New York Public Library once put it, a burial ground for the "indigent, poor, criminals, and victims of epidemic." Historians have estimated that as many as 20,000 New Yorkers may have been buried during the field's nearly 30-year run.

Archeologists discovered four bodies in the park in January 2008 while conducting soil tests for a planned park renovation, and a tombstone was excavated from a 6-foot-deep construction site the next fall. It's since been identified as the tombstone of James Jackson, an Irish immigrant who died of yellow fever. The NY Times reports that bones were discovered during the installation of the park's arch in 1895, and again during a Con Ed project in the 1960s.

In 2005, the Emergency Coalition to Save Washington Square Park tried—and failed—to sue the City, claiming that any renovations to the Park would be disrespectful to the thousands of bodies allegedly buried between 8 and 13 feet below the surface.

Since Tuesday, the DDC has blocked off the excavated area to pedestrians and car traffic, and made way for a crew of archeologist and anthropologists to study the vault, which is about 8 feet deep, 15 feet wide and 20 feet long. Williams couldn't confirm the most recent bone count, but assured us that "we're still finding more things."

"Working together with the Landmarks Preservation Commission, DDC will evaluate the extent and significance of the vault and its contents," said Commissioner Feniosky Peña-Mora in a statement. "We are redesigning the [water main] work to accommodate findings of importance."