Bomb threat forces evacuation at Utah spy site, FBI says Mon May 21, 2012 7:28pm EDT (Reuters) - A bomb threat forced the evacuation of a National Security Agency facility under construction in Utah on Monday but investigators found nothing suspicious, an FBI spokeswoman said. The site for the spy agency is being built at Camp Williams, a military base just south of Salt Lake City. The Army Corps of Engineers is overseeing the project. FBI spokeswoman Deborah Bertram declined to say how the threat was received but said it led to an evacuation at the site. FBI agents spent several hours at the site after the threat was received. "We found nothing suspicious," Bertram said. U.S. officials have released few details on the purpose of the National Security Agency center. The agency is in charge of collecting and analyzing foreign communications and protecting U.S. government communications and information systems. Reporting by Jennifer Dobner in Utah; Writing by Alex Dobuzinskis; Editing by Bill Trott