A portion of National Highway 66 collapsed in Kollam on Friday, triggering panic across the region. No casualties were reported.

A section of the highway and an adjacent service road caved in near Mylakkadu in Chathannur, close to Kottiyam, in the evening. The retaining wall of an under-construction flyover gave way, pulling down the newly built service road with it.

Several vehicles, including a school bus, were trapped on the damaged stretch.

Traffic towards both Thiruvananthapuram and Kollam came to a standstill. Local MLA G A Jayalal rushed to the spot. PWD Minister P A Mohammad Riyas ordered a probe and directed his secretary to seek a report from the National Highways Authority of India (NHAI) immediately.

The collapse has revived long-standing concerns about NH-66, one of the most politically contested road projects in the state.

It has also opened a new round of accusations between Kerala’s ruling Left, the Congress, and the BJP-led Centre.

Congress took to X and wrote: “NH-66 has become a symbol of what happens when warnings are ignored and public safety is treated as an afterthought. The collapse in Mylakkadu, Kollam is not an accident — it is the direct result of flawed designs, overlooked alerts, and a construction process tainted by haste and corruption.”

Kerala Congress also posted a message, citing an earlier collapse near Kottakkal. “What does it tell you about the quality of construction of the much touted NH construction? Can you guess the actual amount of money spent in the construction compared to the inflated contracts given? NH-66 is turning out to be a ticking time bomb which can collapse at any place at any time.”

It added: “Nitin Gadkari will stay silent because he made the money, at maybe 200 Cr per month or more. Now it is left for the people to fend.”

During Zero Hour in the Lok Sabha on Friday, Congress MP Shashi Tharoor called for urgent intervention, citing repeated collapses, beam failures and structural accidents along the highway.

He listed incidents — from 80-tonne concrete girders falling on vehicles in Eramalloor to collapses on the Aroor–Thuravoor stretch. At least 40 accidents have been reported, he said.

He described the 12.7-km Aroor–Thuravoor elevated corridor as plagued by “poor planning, inadequate lighting and unsafe diversions.”

Tharoor urged the Centre to hold NHAI’s project implementation units accountable and to announce a revised timeline. He demanded a safety audit of all NH-66 construction zones, suspension of high-risk work until clearances are obtained, and faster compensation to victims.

“There is also a need for a systemic review at the ministry level,” he added.

Senior Congress leader K C Venugopal echoed the criticism, alleging “repeated lapses from the part of NHAI.”

Chief minister Pinarayi Vijayan offered a clear defence of the state government.

He said the Public Works Department had “no role” in national highway construction and that the responsibility lay entirely with NHAI.

“Everything related to national highways—from design to technical examination—is handled by the National Highways Authority of India,” he said. “As per our experience, some lapses are happening within the NHAI system. But we have nothing to do with it.”

He also mentioned that “the NHAI is responsible for everything related to a national highway, from design to construction. Our PWD has nothing to do with it.”

Vijayan acknowledged that he had spoken to NHAI officials recently but said such communication was only for updates. However, the CM cautioned against assuming that all national highway projects in the state have problems because of a single incident.