Locals in Shimla, Himachal Pradesh, have alleged “rampant blasting” during the construction of twin tunnels on the Kalka-Shimla National Highway bypass, and have raised concerns over cracks appearing in the foundations and retaining walls of several houses.The project, executed by the National Highways Authority of India (NHAI), has been temporarily halted following complaints from residents.A 65-year-old retired college professor said, “We are three families who jointly purchased land here and subsequently constructed our houses separately. That was almost 10 years ago. We never noticed any unusual activity affecting the foundations, retaining walls, or walls of our houses. But in the last fortnight… we noticed large cracks in the retaining walls and foundations, which are supported by concrete bases because of the hilly terrain.”Surjeet Singh Patial, while pointing to a visible crack in one of the retaining walls near his two-storey house, also said the residents were aware of the ongoing twin-tunnel construction from both sides. “We believe these cracks are due to the tunnelling work.”Patial said the NHAI officials had responded to the complaints and temporarily stopped the tunnelling work while repairs were undertaken.“NHAI has taken note of the situation and stopped the work. Repairs have been started using grouting, crack sealing and other measures. But we do not know whether this will provide a permanent solution,” he said.Another resident, on the condition of anonymity, said, “We spent all our savings on constructing this house, and now the house is also showing signs of damage.”Story continues below this adJust about 15 metres away, another multi-storeyed building houses several independent residential units. One of them belongs to 60-year-old Parshotma Devi.She asked, “There is hardly a wall in my house that has not developed cracks… They appeared within a week. We have been living here for the last 12 years. Why have these cracks appeared only now?”Pointing to a large crack in her kitchen, Devi said, “God knows what is behind those loud noises. Some people say blasting is being carried out, while others say the noise is generated by vehicular movement.”Vineet Sharma, the councillor of Ward 22, said, “There have been numerous complaints about alleged blasting being carried out between 2.30 am and 4.30 am for tunnel construction. Residents believe the cracks are emerging due to blasting. We lodged complaints with the local administration and the Deputy Commissioner, Shimla. Initially, no one paid heed to our concerns, following which we decided to protest.”Story continues below this adHe also said a team of senior administrative officials inspected the affected houses and directed NHAI and the construction companies to stop the work until the damage was assessed and the cause was established. This ward is located in Shanti Vihar, which includes the affected Cemetery area.The house of Brijesh Dhareul, a Cemetery resident, has also developed cracks. Dhareul said, “The under-construction twin tunnels are not straight; there are curves in the alignment. While rocks can be excavated using machinery in some sections, it becomes more difficult in curved sections. We strongly suspect that blasting has been used for rock excavation and cutting.”The NHAI officials, however, denied all claims of blasting at the affected site.The Project Director of the Kalka-Shimla highway project, Anand Dhayia, said the claims of blasting were based on rumours. “Blasting at this site has been suspended since November 2025. Blasting cannot be carried out without the approval of the district administration. So far, there is no permission for blasting for this twin-tunnel section.”Story continues below this adThe Project Manager of Bharat Construction (India) Pvt Ltd, Sadanand Mohanty, said controlled blasting was carried out at another section of the project until November 2025. “That was at another end of the tunnel, near Chalonthi. Later, residents raised objections… We stopped the activity.”About the cracks in the Cemetery area, Sanjauli, he said, “We have started repairing the cracks… installed equipment, including Geodetic Reflective Targets and Ground Settlement Markers, to assess any disturbance or movement affecting the land, houses and the hill.”Shimla Deputy Commissioner Anupam Kashyap said residents had approached him with complaints that the cracks had developed reportedly because of the tunnelling work. “I deputed officials to visit the affected houses and areas. Based on the preliminary findings, we instructed NHAI and its concessionaires to stop the ongoing tunnelling work. The exact cause of the cracks is yet to be ascertained.”A team from the Geological Survey of India (GSI) also visited the affected site to assess the situation and prepare a report on the possible causes of the cracks.Story continues below this adAdditional District Magistrate (Protocol) Gyan Sagar Negi also led a team that inspected the affected houses on Saturday and assessed cracks reported in eight buildings.Meanwhile, CPI(M) leader and former Shimla Municipal Corporation mayor Sanjay Chauhan demanded a high-level inquiry into the project, saying the visible cracks could indicate a larger problem. “If corrective measures are not adopted, these cracks could turn into a catastrophic situation — Cemetery is a densely populated area.”