It was late at night and Anton Telegin was driving toward a sprawling coal mine near Ukraine’s eastern front, using the darkness to avoid Russian attack drones.

Mr. Telegin came to collect his wages for himself and some fellow miners, as he did at the end of each month. But this trip, the day after Christmas, seemed different: Russian troops were outside one of the mine’s remote gates, and he wondered if it would be his last trip to the place where he had worked for 18 years. For the past few months, he and his colleagues have struggled under escalating Russian attacks.

Two days earlier, a strike disabled the factory’s substation, halting operations. Sensing the end, some miners left, taking towels and shampoo from the changing rooms where they scraped the soot off themselves at the end of long shifts.

“People were packing up, already saying goodbye,” 40-year-old Telegin recalled.

Mr. Telegin has not returned to the mine since Christmas and is now in Kiev. The approaching fighting disabled the plant, and on Tuesday Metinvest, the company that owns the mine, announced that the facility is now closed.

The closure of the mine, which is located southeast of the war-torn city of Pokrovskended Ukraine’s desperate attempt to keep it running until the last minute. As the last operating mine in Ukraine that produced coking coal — the primary fuel for steel production — it was vital to the country’s steel industry and, ultimately, to its war effort.

Metinvest offered a salary increase to the miners who stayed despite the dangers. To get to the mining areas closest to the front, they had to walk through miles of tunnels that protected them from attack. The shelling caused frequent power outages, trapping them underground for hours.

“There’s constant shelling, and it’s very close,” Maksym Rastyahaev, head of the mining unit, said in a telephone conversation after his shift at the mine shortly before Christmas. “Only the hardiest workers remained.”

The mine closure is now expected to send shock waves through the economy. Steel production is forecast to drop by more than half, from 7.5 million tons this year to less than 3 million next year, according to Oleksandr Kalenkov, head of the Ukrainian Steel Producers Association. The consequences will affect trade — metal and steel products The second largest export of Ukraine last year — reduce tax revenues and deprive the army of essential materials for the production of armor.

“The impact, in all its aspects, is enormous,” said Mr. Kalenkov.

The mine near Pokrovsko is not the first to fall into the hands of Russia, whose forces are decimated much of the industrial base of eastern Ukraine. But his is the story of Ukraine’s resilience: after curtailing operations following a full-scale Russian invasion in 2022, coal production returned to 3.2 million tonnes in 2023, approaching pre-war levels. That year, many residents returned to Pokrovskhoping that the tide of war is turning in favor of Ukraine.

The mine was an economic lifeline for the area. In 2023, Metinvest employed around 4,500 people at the facility, many of whom spent most of their working lives there. “I am a miner. I don’t know how to do anything else. All I know is how to mine coal,” said Yurii Nesterenko, 35, who has worked there for a decade.

The pay was good and Metinvest’s mining facilities reflected the care. During a visit this summer, the mine boasted flower beds, fountains and an Orthodox chapel adorned with golden icons and intricate ceilings, offering miners a quiet sanctuary for prayer.

However, at the end of the summer of 2024, the first signs of danger appeared. The renewed Russian advance in the east prompted a mobilization that depleted the mine workforce, prompting him to employ women to replace conscripted men. More worryingly, a mine lay in the way Russian pressure on the flanks of Pokrovskoa key military logistics center.

“Everyone was hoping that Ukrainian soldiers would hold the line,” said Vyacheslav Dryha, an engineer who left the mine in the fall and is now in Kharkiv. Some employees began to follow battlefield maps daily, following the Russian advance.

At the end of September, four female workers were killed in strikes in the mine in the same number of days. Two of them were in the laundry, while the other two were waiting at the bus stop. The death chilled the staff, prompting many to leave and join flow of residents evacuating Pokrovsk. Russian forces were less than 10 miles away.

Since then, miners have described more and more frequent strikes. Some chose to drive their own cars to the mine instead of the bus, to better avoid the drones that appeared above them. Mine shaft no. 3, which is located closest to the battlefield, in the village of Piščane, started shelling regularly.

At the beginning of December, when window no. 3 became too dangerous to use, the miners switched to descending into the mine through another shaft further west. From there, they faced a two-hour, six-mile walk through underground tunnels to reach the coalfield below Shaft No. 3. To return, they rode on conveyor belts that transported freshly mined coal.

It was a dangerous job. Power and ventilation systems sometimes broke down due to shelling, forcing miners to evacuate. Yet while the fighting raged above, they still felt safer underground, in the half-dark, nearly 2,000-foot-deep tunnels of the mine.

“The earth itself kind of protects you,” said Volodymyr Kohanevych, who maintained equipment at the mine.

Keeping the mine running as long as possible was crucial for Metinvest, which relied on coking coal to smelt iron ore into steel at its factories further west. Steel is used to make rails for Ukrainian railways, a major traffic artery during the waras well as body armor and helmets for soldiers. At the beginning of this month, Metinvest started the production of protective armor plates for American-made Patriot air defense systems that protect Ukrainian skies.

“We are like a second front, we work for victory,” said Mr. Telegin about miners and steel mills.

But by mid-December, Mr. Telegin and his colleagues knew that this second front was collapsing. Russian troops advanced within a mile of shaft no. 3, raising fears that they could seize it and use its tunnels to encircle Ukrainian positions. In response, the miners, working with the military, began drilling holes under the shafts to plant explosives, according to several workers.

A few days later, around December 20, the shaft was blown up. “Everything collapsed and now everything is stone,” said Mr. Telegin.

The manager of Metinvest, who wished to remain anonymous because he was not authorized to speak, said that explosives were also placed in two other shafts of the plant further west, near the villages of Kotlyne and Udachne, which are still under Ukrainian control today. It is unclear whether they have already been detonated.

From 7,000 tons of coal a day this summer, production dropped to just over 2,000 tons by mid-December, the manager said. The strike at the substation, on Christmas Day, dealt the final blow: the mine closed, and production dropped to zero.

Mr Kalenkov, a steel expert, said the closure of the mine had left Ukraine in an uncertain situation. Importing coking coal to make up for the loss will be expensive and complicated due to the logistical obstacles associated with the war. He expects strain already fragile economybut also reductions in defense industry projects, such as the production of armor for the Patriot systems.

“The loss of the mine definitely hampers Ukraine’s combat capabilities,” Mr. Kalenkov.

Many of the 1,000 or so miners who remained until the end have now moved to cities further from the front such as Kiev, Kharkiv and Dnieper. Some have already secured new jobs in factories, while others are still uncertain about their prospects.

Mr Rastyahaev, 40, who has spent half his life working at the mine, said it was “very painful” to leave the place he helped build and develop. As he said last week, he has yet to hear from his management about the future of the mine.

“Honestly,” he said, “I think it’s over.”