KUALA LUMPUR: A sinkhole that opened up along Jalan Masjid India yesterday, which swallowed an Indian tourist, has been attributed to the area's unique geological conditions and recent weather patterns.
Dr Nor Shahidah Mohd Nazer, an expert in geological engineering and soil mechanics from Universiti Kebangsaan Malaysia (UKM), said the situation was most likely exacerbated by heavy precipitation that the city experienced earlier, leading to ground saturation and fast flow of underground water.
"The sinkhole's formation can be traced to the Jalan Masjid India's vulnerability due to its position at the confluence of Klang and Gombak rivers.
"Numerous channels or tributaries exist under the ground and flow into these two major rivers.
"Such conditions caused the ground below to experience continuous undercutting erosion and may create settlement due to soil mobilisation," she told the New Straits Times.
She said the settlement creates a void in the ground that grows bigger over time, especially when underground water flow erodes the surrounding materials, collapsing the wall and soil roof, causing the sinkhole.
She said several key factors contributed to the sinkhole's development.
"This is a common geohazard in the karst region, where limestone - a calcium carbonate rock material, dominates.
"Also, when the ground is made of soil and conditions such as underground water channels exist, or dispersive material occurs, the possibility of sinkhole is also high.
She said heavy rainfall can reactivate seasonal underground channels, which may remain dry during hot weather but become filled with water during the rainy season.
She said this would accelerate underground erosion, often goes unnoticed, and contributed to the collapse of the ground.
In the wake of the incident, the local authorities or respective agencies are urged to take immediate action to enhance public safety and prevent future occurrences, she said.
She said comprehensive sinkhole mapping and monitoring must be carried out across urban and densely populated areas in the Klang Valley.
"Utilising ground scanning techniques, such as geophysics, is crucial for identifying potential voids beneath the surface.
"This proactive approach will allow for early mitigation efforts, helping to avert the occurrence of hazardous sinkholes in the future."
Shahidah said those near the sinkhole-prone areas to be aware of ground conditions.
Specifically, they should look for signs like circular cracks, which could indicate the onset of ground settlement and potential sinkholes.
Yesterday, 48-year-old Indian national Vijayaletchumy, from Kuppam, Andhra Pradesh, India, fell into a sinkhole that opened up at her feet in Jalan Masjid India.
She was walking with her family through an area in front of the Malayan Mansion, Jalan Masjid India before she fell into a sinkhole that had opened up under her at 8.20am.
The search and rescue operation conducted only found a pair of slippers belonging to her near the location after almost 17 hours of searching yesterday.
The search and rescue operation is still ongoing.