Construction workers in Boston made a frightening discovery last week. They found what appeared to be a human skull buried in concrete.

The Office of the Chief Medical Examiner has since confirmed that the skull was “fake,” The Boston Globe reported Monday.

The construction crew was sawcutting along the pier of the city’s Black Falcon Terminal when they found the skull and alerted authorities, the Suffolk County District Attorney’s Office told Boston’s NBC 10.

One worker said that he and others on the job “could not believe” the sight, NBC 10′s Erin Logan reported. Photos shared to NBC 10 showed what looked like a skull popping out of the concrete.

Former Massachusetts State Police trooper Todd McGhee told the NBC affiliate that “a gut reaction” was to “make some connection to a mob hit.” Several notorious organized crime groups have called the Boston area home over the years, including the Patriarca crime family, the Charlestown Gang as well as the Winter Hill Gang, which was led by James “Whitey” Bulger, who was once just a slot behind Osama bin Laden on the FBI’s Ten Most Wanted Fugitives list.