Rescuers work in a flooded cave in Xaisomboun province, Laos, May 29, 2026. Metta Tham Rescue Kalasin via AP
HONG KONG — Personnel engaged in the rescue operation within submerged caverns in Laos have indicated they perceived a "rapping sound" emanating from the depths of the cave system while attempting to free two individuals who have been missing for almost a fortnight.
A contingent of seven local residents ventured into the caverns in Xaisomboun province on May 19 with the objective of prospecting for gold, but found themselves confined due to sudden inundation following torrential rainfall.
Five of the villagers were successfully extracted last week — one of whom received instruction in scuba diving to navigate their way to the cave’s exit. The recovery team managed to discharge sufficient water from the enclosure to permit four more individuals to egress unaided.
Rescue efforts are presently focused on investigating a sixth subterranean chamber where the two remaining men may be situated. One of the individuals coordinating the operation conveyed via social media posts that team members detected a "tapping sound" that appeared to reciprocate their own taps.
Rescuers work in a flooded cave in Xaisomboun province, Laos, May 29, 2026.Metta Tham Rescue Kalasin via AP
"Yesterday, upon striking the cave walls, we received a responding signal. It was a distinct rapping sound, designed to be audible. Based on our preliminary analysis, this is not considered to be a reverberation or an echo of the noise," Kengkaj Bongkawong — the leader of the Thai Metta Tham Rescue Kalasin group involved in the endeavor — stated on Facebook.
"Moving forward, our approach will transcend simply waiting for the water levels to decrease," Bongkawong further commented.
Personnel are employing LiDAR technology and satellite imagery to survey the vicinity and provide assistance to the recovery operations, according to Bongkawong. "We have acquired a substantial amount of valuable data for confirming geological strata and analyzing the subterranean structure to identify potential cave shafts, vertical conduits, or air pockets that could offer a route directly into the chamber where they are trapped," he elaborated.
The villagers who were liberated last week received immediate medical attention at the cave’s ingress. One individual who was recovered on Friday was transported to a medical facility.
Subaquatic specialists from various international locations traveled to the site to contribute to the rescue missions. Authorities have indicated that the cave’s narrow passageways necessitated the involvement of divers with slender physiques to successfully navigate the confined spaces.
Australian speleonaut Josh Richards, who was participating in the rescue initiative, shared with ABC News regarding the successful retrieval of the initial group of villagers, "I was moments away from entering the cave myself when suddenly we heard jubilant shouts and turned around to see four extremely mud-covered miners emerging from the cave entirely on their own."
The subterranean network is characterized by highly constricted, fractured tunnels, and the men were discovered at a distance exceeding 800 feet from the entrance, down a steep incline of 45 degrees below the surface.
Sourse: abcnews.go.com