NYC police probe sewer intrusions after viral videos raise alarm

New York City police are investigating three separate incidents in which groups were filmed entering and exiting the city's sewer system in Brooklyn and Queens, raising concerns about the security of one of the nation's most sprawling underground infrastructure networks.

The incidents cast a spotlight on the vulnerability of New York's 7,400-mile underground sewer network and reignited debate over urban exploration culture, where thrill-seekers venture into tunnels that authorities call both illegal and life-threatening.

Police said they do not believe the incidents represent a threat to the public, though investigations remain open. Surveillance footage that circulated online shows the individuals entering maintenance holes equipped with headlamps, hip waders and tools, according to The Korea Times. Some groups appeared to spend up to three hours underground, and the videos suggest careful advance planning.

Steve Duncan, 48, a former urban explorer who spent years documenting New York's tunnels, said the preparation evident in the footage points to genuine curiosity rather than criminal intent. "They did their research," Duncan told The Korea Times. He noted that experienced sewer explorers time their entries around rainfall patterns and daylight hours to reduce risk.

Duncan described the city's underground as a hidden world shaped by centuries of growth. The older sewer mains, many dating to the 19th century, can exceed 6 feet in diameter — wide enough for a person to walk upright. Large portions of the system trace the courses of rivers and streams buried as the city expanded. "These old streams, they get put underground as cities grow up around them," Duncan said. "It's amazing how much this old natural environment is part of the city today."

The hazards, however, are severe. Water in some passages runs a foot deep over slick surfaces, and the air can carry dangerous concentrations of hydrogen sulfide and other toxic gases, requiring explorers to carry gas meters. The insect life presents a constant menace. "They're all over the place, crawling on walls, dropping down on you. They were the worst," Duncan said of cockroaches. He was hospitalized twice with badly infected extremities during his years of exploration.

Experts warned against treating the incidents lightly. Magued Iskander, an engineering professor at New York University, said the tunnels have real potential for misuse. "Sewers can serve as entry or exit points to buildings, and we have all seen movies in which criminals escape jail through a sewer. There must be a reason beyond mere thrill to enter a dirty place like a sewer," Iskander said, according to The Korea Times. David Sarni, a retired New York Police Department detective and professor at John Jay College of Criminal Justice, echoed the concern: "Is this something that could be exploited by people who look to do harm? You have to really take nothing for granted and always think, unfortunately, on that negative side."

The current cases are not the first of their kind. Three men were charged with burglary and other counts in 2025 after police caught them searching for gold and jewelry in a Brooklyn sewer. About a decade earlier, officers apprehended three others — including a city Department of Environmental Protection worker — emerging from a maintenance hole.

Duncan dismissed treasure hunting as a plausible motive for the latest entries. "These are terrifying places that take a lot of planning and dedication to explore safety. You don't do all of these things for the tiny chance of finding a diamond earring," he said. The real pull, he argued, is more elemental: "The real reason is to see something new, or experience the city in a different way. That's the real lure."