Gurugram, March 11 -- Authorities remained in the dark about the fatal wall collapse that left seven men dead at a construction site in Gurugram's Bilaspur for over two hours Monday night and learned of the tragedy only after a hospital across the border in Rajasthan alerted them, officials aware of the matter said on Tuesday. The incident occurred around 7.30pm at a sewage treatment plant being constructed at an upcoming residential project. A concrete retention wall collapsed, triggering a soil cave-in that trapped workers. Critically, no official at the site sent any alert or sought help from local authorities with jurisdiction over the area, officials cited above said. All seven deceased and four injured workers were taken to a government hospital in Bhiwadi, Rajasthan - approximately 8km from the accident site. Officials from the Rajasthan health department then alerted Gurugram Police, who finally learned of the incident around 9.30pm. DCP (Manesar) Deepak Kumar Jewaria confirmed the timeline. "The incident had taken place by 7.30pm. However, we reached there after receiving an alert from the hospital by 9.30pm," he said. The bodies were sent to Gurugram Civil Hospital Tuesday morning for autopsies and documentation. The National Disaster Response Force, State Disaster Response Force, and civil defence teams were eventually roped in for rescue work after the matter came to light. The deceased were identified as Shiv Shankar, Parmeshwar Mahto, Mangal Mahto, Bhagirath Gope, Sanjeev Gope, and Dhananjay Mahto from Jharkhand, and Satish Kumar Yadav from Deeg, Rajasthan. Injured workers include Indrajeet, Chote Lal, and Shivkam from Nepal, and Deen Dayal Sharma from Dausa, Rajasthan. Vishnu Kumar Yadav, brother of deceased Satish, alleged that private bouncers kept them away from the accident site. "We visited at least two to three hospitals and were finally able to find his body at the government hospital in Bhiwadi after four hours," he said. Satish, a supervisor at the site for the past six months, is survived by his wife Radhika and five-year-old son Rishabh. Vishnu said firm officials have promised financial assistance of Rs.50 lakh for the family. An FIR was registered Tuesday against firms Signature Global, Balajee Infratech & Constructions Pvt Ltd, injured contractor Deen Dayal Sharma, project manager Dinesh Veer, and site safety officer Vikas Pandey under sections 105 and 125 of the Bharatiya Nyaya Sanhita. Sandeep Turan, public relations officer of Gurugram police, said the FIR was based on allegations by Satish's second brother Murari Yadav. "Necessary equipment was also unavailable at the spot which resulted in the death of his brother and other workers," Turan said, quoting the FIR. The project manager and site structure engineer were arrested Tuesday night and will be produced in court Wednesday. Gurugram deputy commissioner Ajay Kumar formed a committee headed by Manesar SDM Dharshan Yadav to investigate negligence. The Haryana labour department ordered construction halted after an inspection found "large-scale safety violations", officials said....