AdvertisementDuring World War I, Germany Unleashed 'Terrorist Cell In America'February 25, 2014facebookEmailA fireboat sits amid ruins and debris on the piers at Black Tom Island in Jersey City, N.J., on July 30, 1916. Evidence pointed to German sabotage. In Dark Invasion, Howard Blum explores Germany's spy network and sabotage efforts in the U.S. at the beginning of World War I. (AP)