MUMBAI, April 30 -- A police constable, Santosh Gopal Chavan, attached to the Nehru Nagar police station in Kurla East, died on Tuesday night after a piling machine toppled on his two-wheeler ahead of the T-Junction in Mankhurd, where the Brihanmumbai Municipal Corporation (BMC) is constructing a flyover. This marks the third accident at an infrastructure site in the city in the last two months. On February 14, a concrete slab from the under-construction Metro line 4 in Mulund collapsed on a moving auto-rickshaw, killing one and injuring three others, while on Monday, motorists had a close shave at the same site when a wooden plank fell from the elevated structure on to a passing car, leaving only a dent. Both accidents occurred barely 10 meters away from one another. Tuesday's accident occurred as Chavan, 48, was driving by the site when the piling machine that was standing on loose soil on the road toppled on him. He was declared brought dead at the hospital. Police have registered cases against two BMC contractors, their engineers, site supervisors, piling machine operators and helpers, who were in-charge of the job. According to the Nehru Nagar police, Chavan, a resident of Neral, Navi Mumbai, although posted at the Nehru Nagar police station was working in the east region additional police commissioner's office in Chembur. An officer from the Mankhurd police station said: "Chavan left home at around 9 pm on Tuesday, crossing the T-Junction at Mankhurd around 9.45 pm, heading towards Vashi. Construction work of a flyover was going on at the time by contractors appointed by BMC. A piling machine deployed for the work, tilted and fell on his chest." Chavan was trapped under the heavy machine. Vehicle owners driving by stopped at the accident site, collectively pulled him out and rushed him to the nearby MGM Hospital in Vashi. "He was declared dead on arrival at the hospital," said DCP Zone VI, Sameer Shaikh. Preliminary investigations have revealed that BMC had given the contract to construct the flyover to private contractors. Their rash and negligent act led to the accident as they had stationed the piling machine on loose soil, said a police officer. "We have registered the case based on the complaint of the deceased's brother Ashok, who also works as a police constable in Vikhroli police station," said the officer. Police said offences have been registered against SFAR Infratech Company's owner, Rehan Mohammed Aslam Shaikh; engineer, Ranjan Kumar Shukla, and site supervisor, Shahir Mukthar Shaikh. They have also booked the owner of Lifting and Lashing Solutions India, Mohammad Saud Haider Ali Chaudhari; engineer and supervisor Salman Imran Khan; piling machine operator, Sudipta (Raja) Dayal; and helper Rijju Bishwas for causing death by negligence. Chavan is survived by his wife, a son and a daughter....