As the clock struck eight minutes past two in the morning of 30 July 1916, a huge explosion woke the people nearby the New York Harbor. Just 40 minutes later, another smaller explosion occurred, detonating an estimated two million pounds (910,000 kilograms) of small arms and artillery ammunition stored at depots on the island formerly known as “Black Tom.”

Black Tom Island Bombing of 30 July 1916

The first tremendous explosion shattered glass windows throughout Jersey City, lower Manhattan, and Brooklyn, even jolting the massive Brooklyn Bridge. People as far away as Maryland and Philadelphia felt the blast, which would have been recorded as a modern earthquake on the Ritcher scale between 5- and 5.5-magnitude. Some window panes in Times Square and stained glass windows in St. Patrick’s Cathedral were also shattered, but perhaps the most significant damage done was on the torch of the Statue of Liberty. Soaring shards of shrapnel pockmarked the torch, effectively closing it from visiting tourists for good. Yes. Before the 1916 attack, you could climb the very top of the Statue of Liberty. It’s been well over 100 years now.

Boston Daily 1916
(Image source: Wikimedia Commons)

Property damage from the explosion amounted to some $20,000,000, which equates to over half a billion in 2023 dollars and another $100,000 (nearly three million in 2023 dollars) worth of damage to the Statue of Liberty alone. Four people were reported dead, including the barge captain, two police officers, and a ten-week-old baby thrown out of the crib due to the blast wave. However, some speculated that the actual number of fatalities was much higher as many destroyed barges anchored around the pier served as shelters for vagrants and immigrants.

Either way, the incident shocked the nation. Many see this as a terrible accident caused by gross negligence rather than a deliberate attack. Meanwhile, a few others had rousing suspicions, particularly toward bitter Germans, who had trouble getting munitions from neutral America due to the British naval blockade. This is the World War I era, after all.

It’s just that, without concrete evidence, this suspicion remains a baseless hunch.

Packed With Explosives

The man-made island of Black Tom was home to America’s largest munition depot, with dozens of warehouses storing thousands of tons of munitions, explosives, and black powder from New York and New Jersey factories. It was where military goods were being kept before being shipped to customers across the Atlantic, which at that time was the First World War belligerents.

Despite environmental hazards and a previous fire accident that likewise caused an explosion in 1875, the island was bustling and thriving. Later, adding a railbed directly connected the island to Jersey City.

At first, as European countries began tearing each other apart, America refused to get involved and stuck to its guns by staying neutral. Instead, we focused on making a profit off the war by selling munitions to whoever would buy them. That means either the Allied or Central Powers could procure munitions from us. Regardless of this fact, the blockade of the Royal Navy caused Germans to be unable to transport its purchased military supplies from America to its troops—leading the Central Powers to opt for Plan B: Sabotage.

Black Tom Island
Map of Black Tom Island – Showing the area damaged by the explosion (Image source: Library of Congress)

With no intelligence agency founded yet in the US to monitor and investigate such activities, Germans living stateside easily slipped in and established a network of spies. The latter would secretly draft stranded German soldiers in neutral ports and German Americans across the country, overseen by Count Johann von Bernstorff, the German Ambassador to the United States.

Bernstorff, while maintaining good relations with Americans, has been doing underground intelligence work to support the German war effort. At first, he tried to buy off the shipments to Britain to cut off its munition supplies, but the US production was too immense and fast-paced. He tried to influence American officials into siding with them in the war, and when that didn’t work, Bernstorff began sponsoring sabotage missions.

Recruited German agents would set fires or plant timed bombs on ships bound for Axis Powers countries, destroying goods as they stemmed across the Atlantic Ocean. The attack at Black Tom was the Germans’ most heinous sabotage yet against its enemies.

Lack of Security, Vulnerable To Attacks

Lax America was confident against potential attacks, with a vast ocean separating the country from conflicted Europe during World War I. What we didn’t see coming was the Germans wandering around the country equipped with a strong nationalist belief, who were willing to do everything to contribute to the war effort against the English.

As mentioned earlier, Black Tom Island was the largest ammunition depot in the United States at the time, but with no imminent threat, it was left unprotected.

This ended up being an easy task for German spymaster Franz von Rintelen who was tasked to surveil and map out the storage sheds around the pier a year before the attack. Rintelen then recruited three men to carry out the operation via the German Consul General.

Polish-born Lothar Witzke was serving as a German naval lieutenant when he escaped from an internment camp following the sinking of his ship off the South American coast in late 1915. He arrived in San Francisco, where he met Kurt Jahnke, a naturalized American German and a US Marine veteran, who likewise was recruited via the German Consul General. By June 1916, both men left the state for New York, where they would connect with the last member, Michael Kristoff, a 23-year-old Austrian immigrant who briefly served in the US Army.

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With security lacking, the three men eased their way into the depot, with one on foot and two others via a rowboat. On the evening of 29 July 1916, the saboteurs wired the facilities packed with explosives, set small fires near boxcars brimming with TNTs and gunpowder, and like previous tactics, surrounded the warehouses and barges with time-delayed bombs. After setting everything up, they quickly fled the scene.

Shortly after two in the morning, an earsplitting explosion rocked Black Tom Island and its neighbors.

The sky over New York and New Jersey turned yellow as thousands of pounds of explosives exploded hundreds of feet in the air. Warehouses, piers, barges, and even the artificial island itself were obliterated. For days, artillery shells and other weapons detonated, and when the flames and smoke finally cleared, the massive damage over Black Tom made its former self barely recognizable.

America Was Never the Same

With no appropriate agency to conduct a thorough investigation in place, despite suspicion of sabotage, the catastrophic incident in Black Tom was initially concluded to be caused by gross negligence. Investigators from the New York Police Department’s Bomb Squad had raised suspicions against German agents. However, with a lack of evidence and specifications on who did it, they failed to pursue the case.

The investigation moved on to the arrest of two watchmen on suspicion of manslaughter. According to police, these men may have left smudge pots, which were lit to keep away mosquitoes, unattended. Nevertheless, a subsequent inquiry found that the pots did not start the fire, concluding that the explosion was merely a tragic accident.

It wasn’t until three years after World War I ended that the real culprit was determined, pointing investigators to German operatives. By this time, the US had established its domestic intelligence agency and passed Espionage and Sabotage laws.

Kristoff was the first one to be arrested by the Jersey City police on suspicion of involvement in the Black Tom sabotage, but without concrete evidence, he was eventually released. Nonetheless, the Austrian immigrant would continue to drift in and out of prison for various crimes until his death in 1928 due to tuberculosis.

Meanwhile, German Consul recruits Jahnke and Witzke crossed the border over Mexico shortly before the United States joined the war. They continued their nationalist agenda, stirring up anti-American sentiments and organizing sabotage operations. Witzke would be the first of the duo to be arrested when the US Army discovered his movements. He would be sentenced to death after being found guilty of espionage but was later pardoned in 1923. Jahnke, on the other hand, evaded authorities altogether and even returned home to Germany in 1921, where he served as an intelligence agent for the Nazi regime until 1945, when the American German was captured and executed by the Soviets.

For more in-depth reading, check out Sabotage Black Tom by Jules Witcover.