Deep, dark & deadly: Inside Umrangso mine rescue operation

In the early hours of January 6, the tranquil hills of Umrangso in Assam’s Dima Hasao district were shaken by a crisis that would soon grip the nation’s attention. Nine miners found themselves trapped deep within the dangerous confines of an illegal rat-hole coal mine as water from an adjacent abandoned mine surged in, flooding their only exit.

The sudden flooding occurred in the Tin Kilo area of Umrangso, trapping the miners approximately 300 feet underground. What followed was a 44-day-long intensive rescue operation that tested the resilience and determination of multiple agencies, including the National Disaster Response Force (NDRF), State Disaster Response Force (SDRF), the Indian Army, and the Navy.

The challenges faced by the rescue teams

The rescue operation was fraught with several obstacles, the most significant being the high water levels, unstable terrain, and lack of visibility. The depth of the mine, reaching nearly 350-400 feet, posed an enormous challenge for the rescuers.

Rescue team going inside the rat hole mine in the trolley

According to an NDRF official, "The depth of the mine was a major challenge. Working at around 350-400 feet underground is extremely difficult. When we first arrived, the mine was flooded, and we had no idea about the exact water level or mine depth, making it unsafe to send rescuers. However, our team managed to measure the depth using specialised equipment. We were also joined by deep divers from the Navy, and we worked together to assess the situation."

One of the primary difficulties was the presence of water inside the mine. High-powered pumps were deployed to dewater the mine, but it took weeks for the water level to reduce significantly. The rescue team also had to contend with extremely low oxygen levels within the mine, which posed a severe threat to those venturing inside.

NDRF Inspector Raushan Kumar Singh, the team commander, while describing the unique challenges they encountered, said that the coal mine operation was a learning experience for them. "Previously, we had only conducted vertical coal mine operations, but this Umrangso rat-hole mine was a horizontal one. After dewatering, we found the tunnels had a zig-zag shape at great depth. We had to use ropes to navigate inside, as our communication devices failed underground, forcing us to rely on rope signals," said Singh.

Another challenge was the one-ton capacity crane trolley, which could only accommodate a few rescuers at a time. "Additionally, we had no prior knowledge of the tunnel structure, making navigation difficult. However, the local people of Umrangso played a vital role in the dewatering process. They operated pumps and provided crucial insights into the underground layout, which helped us plan our approach. In the first phase of the operation, we stayed in tents near the site, and in the second phase, we shifted to a guest house," he said.

The water level inside the mine remained a persistent challenge. Motors and pumps were used continuously to drain water, but the process was slow, often requiring the rescue team to halt operations temporarily. The official elaborated on the difficulties, "Every time we went inside, water would start filling up the mine again. Within an hour, the water levels would rise significantly, forcing us to exit. We had to wait for at least two hours after pumping the water out before resuming the operation."

An Army Special Forces diver recounted the extreme risks faced by the rescue teams. “The depth where the water level started was around 100 feet (30 meters), but our diving sets were only cleared for 50 feet,” he explained, adding that the team had to innovate to push beyond their equipment’s limits.

Initially, they descended gradually—first to 10 meters, then 15—before developing a technique using an anchor and rope to descend quickly while conserving oxygen. “By breathing slowly, we managed to reach 30 meters—beyond our gear’s designed capacity,” he said. The murky water offered zero visibility, turning the operation into an exploration of uncharted territory, where success relied solely on human determination and professional training.

Despite the difficulties, their efforts yielded results. “After dewatering, we retrieved three bodies initially, which gave us hope,” the diver recalled. However, the mine’s narrow, horizontal tunnels posed additional challenges. “There was no space to stand; we had to crawl through sections where the water level remained high. The last four bodies were about 300 feet inside the rat hole, forcing rescuers to navigate the flooded passage for the entire distance,” he said.

While the NDRF had arrived at the site, initial hesitation in entering the mine due to the extreme risks led to the involvement of Army and Navy divers. To ensure safety, they implemented a system where one diver descended while an anchor diver remained above, monitoring time and responding to distress signals by pulling the rope.

Referring to the perilous Thailand Tham Luang cave rescue operation of 2018 where 12 young football players and their coach were trapped inside the flooded cave, the Army Special Forces diver added, "The operation bore similarities to the Thailand Tham Luang cave rescue but was uniquely challenging due to the confined space, lack of air pockets, and submerged sections".

Another major hurdle was the lack of communication. The moment rescuers entered the rat-hole mine, all communication devices failed due to the underground conditions. The only way to coordinate was through eye contact and hand gestures. Additionally, the confined space inside the mine, barely 4-5 feet in width, made movement difficult for rescuers carrying oxygen cylinders and other equipment.

Rescue diver team embarking onto the depths

"Communication was nearly impossible once inside the mine. Despite having advanced tools and devices, as soon as our team entered, all connections were lost. We could only rely on hand signals and eye contact to coordinate inside the mine, making the process even more challenging."

The final breakthrough

The rescue teams withdrew temporarily on January 17, anticipating that it would take a month for the water level to recede to a workable level. On February 5, the second phase of the rescue operation resumed, with the water level gradually reducing. By February 19, the conditions had improved enough for a final attempt. The rescuers, equipped with safety gear and breathing apparatus, re-entered the mine.

"When we first re-entered the mine on February 19, we encountered about 3-4 meters of water. We waited for further reduction and continued to monitor the situation. Finally, when the water level dropped to about 0.5 meters, we decided to go inside regularly in the mornings and evenings, measuring water levels and searching for bodies," said NDRF's Singh.

Despite the improved conditions, recovering the bodies was no easy task. The miners had been trapped for over 40 days, and the bodies were in a severely decomposed state. The retrieval process was slow and required extreme caution. The official explained:

"One of the biggest difficulties we faced was the condition of the bodies. Due to prolonged exposure to water, the bodies had swollen, making it challenging to pack them in body bags and bring them to the surface. On February 19, we retrieved the first of the remaining five bodies at around 150 feet. The stench was overwhelming, and the confined space made it even harder for rescuers," he added.

The remaining four bodies were gradually retrieved in subsequent attempts. The confined nature of the mine, coupled with unstable oxygen levels and the risk of roof collapse, made each retrieval highly perilous.

"Before sending in the final rescue team, our commandant, along with engineers and doctors, personally entered the mine to check safety conditions. Only after a thorough assessment did we proceed with the final phase of the operation. Our deep divers and NDRF team members crawled through the narrow passages to recover the bodies," Singh added.

Rescue teams moving out of the coal mine to resume dewatering

A coordinated effort

The Umrangso mine rescue operation was one of the most challenging missions undertaken in recent years. The involvement of multiple agencies, including the Navy's deep divers and the dedicated NDRF and SDRF teams, ensured that the bodies were eventually recovered despite immense obstacles. The commandant of the NDRF team also played a crucial role in ensuring the safety of the rescuers.

Despite the adversity, the rescue operation highlighted the commitment and bravery of the personnel involved. The teams faced uncharted territories, developed makeshift equipment, and persevered through nearly a month and a half of relentless effort.

Minister of Mines and Minerals, Kaushik Rai, closely monitored the situation throughout the operation. He acknowledged the complexities of the rescue operations, noting that fluctuating water levels, ranging from 1.5 to 2 meters, posed significant challenges.

Additionally, during the course of the operation, Assam Chief Minister Himanta Biswa Sarma ordered a judicial inquiry into the incident, aiming to identify responsible parties and prevent future occurrences of illegal mining activities.

The tragedy has underscored the dangers associated with illegal rat-hole mining, prompting calls for stricter enforcement of mining regulations and improved safety measures to protect workers in the industry.

The crisis in Umrangso serves as a grim reminder of the dangers of illegal rat-hole mining. The 44-day-long operation, culminating on February 19 with the retrieval of all nine bodies, demonstrated the unwavering dedication of the rescue teams.

By February 21, the teams officially concluded the operation and returned to their bases, having achieved their mission against all odds. The support from district administration, various agencies, and the local community played a crucial role in the success of this operation. However, it also raises pressing concerns over the enforcement of mining regulations to prevent such tragedies in the future.