A portion of the Rs 2,000-crore Sohna Highway caved in yet again on Wednesday, marking the sixth major cave-in on the crucial Gurugram corridor since 2023 and reigniting concerns over the crumbling sewer infrastructure beneath one of NCR’s busiest roads.The latest collapse created a massive pit nearly 10 feet wide and 20 feet deep, just metres away from the site where a similar sinkhole had appeared in June last year. Authorities immediately barricaded the affected stretch to prevent accidents, while officials from the National Highways Authority of India (NHAI) said further action would be taken in coordination with the Gurugram Metropolitan Development Authority (GMDA).Officials said the recurring cave-ins had been repeatedly linked to a damaged 1,800-mm master sewer line running beneath the highway. Though the sewer network was officially handed over to GMDA in 2022, the critically damaged master pipeline still has not undergone complete rehabilitation.The issue traces back nearly a decade. In 2017, the then Haryana Urban Development Authority (HUDA), now Haryana Shehri Vikas Pradhikaran (HSVP), had proposed a comprehensive rehabilitation of the sewer line using cured-in-place pipe (CIPP) technology at an estimated cost of Rs 28.75 crore. The proposal also included laying a new 900-mm sewer line from Subhash Chowk towards Sector 48 and strengthening sewer manholes along the stretch. NHAI was expected to execute the project under HUDA’s supervision.However, during the highway widening phase and the subsequent administrative transition from HUDA to GMDA, the scope of the project was significantly reduced. According to NHAI, only the strengthening of manholes was eventually carried out, while the rehabilitation of the main damaged pipeline was left unresolved.Since December 2023, the corridor has witnessed a series of alarming sinkholes, exposing the fragile condition of the underground sewer system. Major incidents were reported in December 2023, July 2024 and May 2025. One of the most serious cave-ins occurred near Sispal Vihar, where a collapsed sewer line and chamber triggered a 12-foot-deep pit.On June 30 last year, another sinkhole — approximately two metres wide and six metres deep — emerged on the same stretch. Earlier, on June 18, a smaller collapse had forced authorities to shut nearly one-and-a-half lanes as a precautionary measure.After prolonged blame-shifting between multiple agencies, it was eventually decided that NHAI would undertake full rehabilitation of the master sewer line using CIPP technology at an estimated cost of Rs 68 crore. However, despite repeated collapses and mounting public safety concerns, the rehabilitation work is yet to begin.