At Seoul's bridge control center, AI helps stop 99% of suicide attempts

Kim Jun-young, chief of the Hangang Bridge CCTV Integrated Control Center, speaks during an interview with The Korea Times at the center in Gwangjin District, Seoul, April 29. Korea Times photo by Choi Won-suk

For most Seoul residents, the Han River is a place for evening strolls, picnics and a brief respite from city life.

But for Kim Jun-young, chief of the Hangang Bridge CCTV Integrated Control Center in Gwangjin District, Seoul, it is where his team pulls people back from the edge every day.

Established in 2021, the center uses artificial intelligence (AI) for comprehensive emergency response, monitoring 900 CCTV cameras across 17 of Seoul's 21 pedestrian-accessible Han River bridges. Beyond suicide prevention, its most frequent task, the center also handles criminal tracking, traffic accidents and drug enforcement.

“We get three to four suspected suicide attempts that result in a dispatch call every day,” Kim said in an interview with The Korea Times. “Most of them go with officers without protest, which means they were determined to end their lives.”

The intervention record reflects the scale of the crisis as well as the effectiveness of the response. According to city data, suicide attempts on Han River bridges have surpassed 1,000 for four consecutive years since 2022, reaching 1,270 dispatch calls last year alone. Of those, 10 resulted in deaths, a survival rate of 99 percent.

Much of that credit goes to AI, which triggers an alarm if an object identified as a person remains for more than 300 seconds in a bridge's "loitering zones," sections where people are able to stand for extended periods.

Surveillance cameras are monitored at the Hangang Bridge CCTV Integrated Control Center in Gwangjin District, Seoul, April 29. Korea Times photo by Choi Won-suk

When a person of interest is flagged, human operators zoom in to determine whether someone is simply out to enjoy the river or contemplating suicide, looking for signs like whether they are crying or smiling. Even small details matter: a bottle of soju, slippers worn in the middle of winter or a chair being hauled onto the bridge.

Once danger is confirmed, speed is everything. For most bridges, rescue units arrive within four minutes, and every second counts before someone goes over the edge.

“Han River bridges average 30 meters in height and for an adult weighing around 70 kilograms, hitting the water from there carries the same force as being struck by a car at 60 kilometers per hour,” Kim explained, adding that is why intervening before a jump is key.

The center also works in close coordination with 119 water rescue units. When operators spot a person in distress on a bridge, both teams monitor the live feed together, with the rescue unit ready to deploy.

The center's reach extends beyond rescue. The system supports filtered searches by gender, age and clothing type — a search for "April 29, male, Mapo," for example, pulls up footage of every adult male who crossed Mapo Bridge that day, helping police map the movement routes of suspects. All data is strictly managed under the Personal Information Protection Act and deleted after one month.

Before AI, operators monitored footage manually, a system a 2017 city audit found falling far short. A subsequent study found a person can monitor a maximum of 12 screens at once. With 422 cameras at the time, full manual coverage would have required about 86 staff. The solution was AI as a first filter, with just 11 operators on duty.

A CCTV monitor screen showing men crossing Mapo Bridge, at the Hangang Bridge CCTV Integrated Control Center in Gwangjin District, Seoul, April 29. Korea Times photo by Choi Won-suk

Still, the technology has its weaknesses. Kim said the system carries a hallucination rate of about 15 percent, including instances where it misidentifies an object as a person, which is why human judgment remains the final call.

For Kim, the most rewarding moments come when a life is saved — news that arrives at any hour, day or night. “Whenever a rescue comes through, I tell my staff 'good work.' That's when I feel most proud,” he said.

Kim never claims to fully understand the suffering of those who come to the Han River thinking of ending their lives. But even a chance to reconsider, he believes, can make all the difference.

“Because death cannot be undone, it may simply be a mistake made in the moment,” he said, adding that the real credit belongs to the firefighters and police.

If someone you know exhibits warning signs of suicide, contact Korea's Suicide Crisis hotline at 109. For foreign language assistance to connect with mental health professionals, call Danuri Portal's helpline at 1577-1366.