For an extended period, Russian forces have launched nightly attacks on cities across Ukraine, endangering civilians and critical infrastructure. Faced with continuous Russian aggression, the air raid warning system has long served as a lifeline, helping Ukrainian citizens find timely shelter and thereby reducing casualties.

Many assume these alerts activate automatically. However, in Kharkov, northeastern Ukraine, this vital task falls to an emergency response center staffed by experts working 24/7.

Deep within this secret underground facility, specialists maintain a state of high concentration, fingers poised for action. If they identify the city as a target for Russian missiles, they must act even before military air defenses engage, activating sirens to warn residents to seek cover.

Air raid sirens have become all too familiar to Ukrainians throughout the four years of conflict. Yet, the operational methods and the individuals behind them have long remained a carefully guarded secret.

Staff members work at Kharkov's secret alert facility. Photo: NYT

The secret bunker and the 'life-or-death button'

Last month, Kharkov city authorities granted rare media access to an emergency response center. Here, civilian expert teams have "saved thousands of lives" simply by flipping a switch and pressing a large red button on a computer screen.

"I try to do everything as quickly as possible, because only then do people get more time to hide," said Dmytro, 23, a specialist at the emergency warning center.

Located just 32 kilometers from the Russian border, Kharkov is a frequent target, with missile and bomb scars covering the city. Over the past year, air raid sirens here have sounded 1,826 times, an average of 5 alerts daily.

Location of Kharkov city, Ukraine. Graphic: RYV

After four years of war, many residents have grown complacent about the threats. When an air raid warning sounds, some still head to basements or subway stations for shelter, or take cover at home between two load-bearing walls. However, an increasing number are becoming indifferent, ignoring the sirens.

To address this 'alert fatigue' among residents, Kharkov Mayor Ihor Terekhov pioneered Ukraine's first zoned warning system. This system allows for more precise targeting of dangerous areas, activating alerts only when the city is truly threatened, rather than sounding based on the general situation of the entire province. Since the new system became effective in early 2025, Kharkov's alerts have been only 50% of the regional total, with no delayed warnings.

"It has been effective, certainly so," said Bohdan Hladkykh, head of Kharkov's Emergency Response Agency, referring to the new system, which cost half a million USD.

While the Kiev region is implementing a similar system, he finds it "unfortunate" that other cities have yet to follow suit.

The warning center is the backbone of the new system, operating under strict security 24/7, with 12-hour shifts. The "lead specialist" is responsible for activating the sirens, with a supervisor seated right beside them.

The specialist's workstation features two computer mice. One performs regular tasks. The other is unique; it activates the city's over 500 air raid sirens. This mouse is disconnected after each use to prevent accidental clicks.

A Ukrainian prosecutor uses a phone to photograph debris from a Russian missile used in an attack on Kharkov in 11/2024. Photo: AFP

The battle of wits

The radar map used by specialists displays a blue circle around the city. A drone entering this circle can approach the city within approximately 7 to 8 minutes. Therefore, as soon as a target crosses this boundary, the specialist immediately activates the sirens.

Much of the work involves patiently waiting to see if a drone or guided bomb enters the threat range. They can change their trajectory or circle the city to target other locations. Specialists always avoid activating alerts too early, fearing it could cause panic among residents and undermine the system's credibility.

However, they do not hesitate for a second if the attacking object is a ballistic missile. Sirens activate immediately upon detection of a launch.

Threats can be identified in several ways. Sometimes, the expert team detects the threat on radar themselves. The warning center also maintains direct contact with the military.

Firefighters extinguish a blaze after a Russian attack on Kharkov in 6/2025. Photo: AFP

The benefit of this was proven one recent night. A military liaison warned the center of a ballistic missile threat, and city sirens immediately blared. In contrast, the regional authority's alert sounded three minutes later.

The alert activation process involves two steps: flipping a switch to activate the phone alert application, used by most Ukrainians, then pressing a large red button on the screen to initiate the city-wide siren system. All this happens in under two seconds.

This job demands a steady hand, a calm mind, and high concentration, according to supervisor Alina Ustiuhova, who added that it took six months to recruit someone for the lead specialist position.

Dmytro, who has held the position for three months, stated he is naturally calm and accustomed to pressure. He remains almost motionless throughout his shift. He keeps his crucial role a secret from his family, part of a process many Ukrainians mistakenly believe is automated.

"I don't want them to know I bear such a significant responsibility," Dmytro explained. "The less they know, the better they sleep."

Vu Hoang (According to Reuters, AFP, AP)