The Mines and Geosciences Bureau in Central Visayas (MGB-7) confirmed Friday that an active sinkhole has formed in Sitio Indilicio, Purok Lib-og, Barangay Guadalupe, Bogo City.

“Field and radar surveys show that the sinkhole in Sitio Indilicio is still expanding, with rumbling sounds and groundwater flow indicating a wider underground cavity system,” MGB-7 said.

The bureau classified the site as a “high-risk ground collapse area” after a field assessment showed that the opening continues to widen due to a water-bearing subsurface cavity.

MGB-7 regional director Al Emil G. Berador said the bureau’s technical personnel conducted the assessment from 22 to 23 August, following reports of ongoing ground subsidence that first appeared as a depression at around 4:45 a.m. on 20 August.

“Please be guided by the following findings, observations, and recommendations for your immediate attention and appropriate action,” Berador said.

The sinkhole is a cover-collapse formation that now measures roughly 15 to 25 meters across after expanding by about two meters between 22 and 23 August.

Drone imagery and a visual survey indicate that the collapse formed above a subsurface cavity about 15 meters below the ground, extending along a north-northwest to south-southeast direction.

The sinkhole is still progressing, with sections of the rim occasionally giving way and collapsing into the cavity below. Geologists said that rumbling sounds heard during the assessment indicate subsurface collapse — a condition that could lead to further enlargement of the sinkhole.

The nearest house stands only about 18 meters from the sinkhole’s expanding rim.

MGB-7 said affected residents have already been briefed on the hazard and advised to evacuate pre-emptively whenever heavy rains occur.

MGB-7 also identified two other cover-collapse sinkholes, located about 100 meters southwest and 65 meters northeast of the new sinkhole. Both reportedly formed following the 2025 Bogo Bay Fault earthquake. They are located on opposite sides of the new sinkhole.

MGB-7 suggests the area may sit above an interconnected or laterally extensive underground cavity or conduit system, rather than an isolated collapse.

A ground-penetrating radar survey was conducted to determine the extent of the underground cavity.

However, the signals were attenuated beyond a depth of five to six meters because of the clayey composition of the subsurface layer.

As a result, the cavity’s full depth and lateral extent could not be confirmed.