Black Tom explosion The Black Tom explosion on July 30 , 1916 , in Jersey City , New Jersey , was an act of sabotage on American ammunition supplies by German agents to prevent the materiel from being used by the Allies in World War I . Black Tom Island . The term " Black Tom " originally referred to an island in New York Harbor next to Liberty Island . The island received its name from a local legend of an African American resident named Tom . By 1880 , a causeway and railroad had been built connecting it to the mainland for use as a shipping depot . Between 1905 and 1916 , the Lehigh Valley Railroad Company , which owned the island and causeway , expanded the island with landfill , resulting in the addition of the entire area to the limits of Jersey City . The area contained a mile - long pier that housed the depot as well as warehouses for the National Dock and Storage Company . Black Tom was a major munitions depot for the northeast . Prior to a 1915 blockade of the Central Powers by the Royal Navy , American industries were free to sell their materials to any buyer , but henceforth the Allies were the only possible customers . It was reported that on the night of the attack , two million pounds ( 1 kiloton ) of ammunition were being stored at the depot in freight cars , including one hundred thousand pounds of TNT on the " Johnson Barge No . 17 " , all awaiting eventual shipment to Britain and France . Jersey City ' s Commissioner of Public Safety , Frank Hague , reported he had been told the barge had been " tied up at Black Tom to avoid a twenty - five dollar towing charge " ( US $ in 2018 ) . Explosion . After midnight , a series of small fires was discovered on the pier . Some guards fled , fearing an explosion . Others attempted to fight the fires and eventually called the Jersey City Fire Department . At 2 : 08 a . m . , the first and largest of the explosions took place . Fragments from the explosion traveled long distances , some lodging in the Statue of Liberty and some in the clock tower of " The Jersey Journal " building in Journal Square , over a mile away , stopping the clock at 2 : 12 a . m . The explosion was the equivalent of an earthquake measuring between 5 . 0 and 5 . 5 on the Richter scale and was felt as far away as Philadelphia . Windows broke as far as away , including thousands in lower Manhattan . Some window panes in Times Square were completely shattered . The stained glass windows in St . Patrick ' s Church were destroyed . The outer wall of Jersey City ' s City Hall was cracked and the Brooklyn Bridge was shaken . People as far away as Maryland were awakened by what they thought was an earthquake . Property damage from the attack was estimated at $ 20 million ( US $ million in 2018 ) . The damage to the Statue of Liberty was estimated to be $ 100 , 000 ( US $ in 2018 ) and included the skirt and the torch . Immigrants being processed at Ellis Island had to be evacuated to lower Manhattan . Reports vary , but as many as seven people may have been killed , including : Injuries numbered in the hundreds . Smaller explosions continued to occur for hours after the initial blast . Investigation . Two of the watchmen who had lit smudge pot s to keep away mosquitoes on their watch were immediately arrested . It soon became clear that the fires of the smudge pots had not caused the fire and that the blast had not been an accident . It was traced to a Slovak immigrant named Michael Kristoff , who had served in the U . S . Army , but admitted to carrying suitcases for the Germans before America entered World War I . According to him , two of the guards were German agents . It is likely that the bombing involved some of the techniques developed by a group of German agents surrounding German ambassador Count Johann Heinrich von Bernstorff , using the cigar bomb s developed by Doctor Walter Scheele . Although suspicion at the time fell solely on German saboteurs like Kurt Jahnke and his assistant Lothar Witzke , still judged as " likely " responsible by some , later investigations in the aftermath of the Annie Larsen affair unearthed links between the Ghadar conspiracy and the Black Tom explosion . Later investigations by the Directorate of Naval Intelligence are known to have found links to some members of the Irish " Clan na Gael " group , the Indian " Ghadar Party " , and Communist elements . The Irish socialist James Larkin asserted that he had not participated in active sabotage but had encouraged work slowing and strikes for higher wages and better conditions in an affidavit to McCloy in 1934 . The Statue of Liberty ' s torch was closed to tourist traffic after the explosion . Since then and as of 2013 , it has not been opened to the public , but is being maintained by park personnel . The Lehigh Valley Railroad Company , advised by John J . McCloy , sought damages against Germany under the Treaty of Berlin from the German - American Mixed Claims Commission . The commission declared in 1939 that Imperial Germany had been responsible and ordered damages . The two sides finally settled on $ 50 million in 1953 ( US $ in 2018 ) . The final payment was made in 1979 . Black Tom today . Landfill projects later made Black Tom Island part of the mainland and it was incorporated into Liberty State Park . The former Black Tom Island is located at the end of Morris Pesin Drive in the southeastern corner of the park , where a plaque marks the spot of the explosion . A circle of American flags complement the plaque , which stands just a bit east of the visitors ' center . The inscription on the plaque reads Explosion at Liberty ! On July 30 , 1916 the Black Tom munitions depot exploded rocking New York Harbor and sending residents tumbling from their beds . The noise of the explosion was heard as far away as Maryland and Connecticut . On Ellis Island , terrified immigrants were evacuated by ferry to the Battery . Shrapnel pierced the Statue of Liberty ( the arm of the Statue was closed to visitors after this ) . Property damage was estimated at $ 20 million . It is not known how many died . Why the explosion ? Was it an accident or planned ? According to historians , the Germans sabotaged the Lehigh Valley munitions depot in order to stop deliveries being made to the British who had blockaded the Germans in Europe . You are walking on a site which saw one of the worst acts of terrorism in American history . A stained glass window at Our Lady of Czestochowa Catholic church memorialized the victims of the attack .