From their headquarters in the Spotswood Hotel in Richmond, Virginia, Singer and his agents set up secret workshops all over the South in coastal cities. During their two years of operations they blew up ships, trains, and railroad bridges killing a large number of people. Most of their missions were done at night close to Union patrol boats and sentries. Northern newspapers called Singer's inventions "infernal machines" and condemned their use as unchristian and assassinations of the worst kind. To cover up who they were and what they had done, their records were burned at the end of the war. They were constantly hunted as saboteurs and spies by Northern authorities. Admiral David Dixon Porter ordered that any of Singer's agents were caught with any of these inventions they were to be "shot on the spot". Names and descriptions of Singer's operatives were distributed by Union commanders. 