A downed 100-year-old oak tree in New Haven turned out to have a human skeleton tied up in its roots.

One hypothesis:

The skeleton could belong to a victim of smallpox, interred in what amounted to a “mass burial site.”

As evidence, he cited a passage in the New Haven Green chapter of the book, “Historical Sketches of New Haven.” The book describes how some notables, beginning with Martha Townsend, were buried in the walled-off cemetery behind the Center Church on the Green. Others were buried in the rest of the Upper Green, apparently with great density.

“Sometimes, at the dead of night, apart from the others, the victims of smallpox were fearfully hid here,” the book reads. “The ground was filled with graves between the Church and College Street; sixteen bodies having been found within sixteen square feet.”

The last bodies were buried there in the 1700s, Greenberg said. In 1821, the stones were moved to the Grove Street Cemetery, and the ground was raised to level off the Green. The bodies remained behind.

Happy Halloween.