MUMBAI, April 25 -- A wedding celebration turned tragic in Bhandup on Thursday night when a 25-year-old guest died and 10 others were injured after falling into an uncovered sewage treatment plant (STP) pit at a nearby under-construction building. Police said the pit had been inadequately covered with wooden planks and steel sheets and have booked the builder. The deceased, Bhalchandra Falle, was attending a function at Mateshwari Hall near Kaka Petrol Pump when the incident took place around 11pm. According to police, the events unraveled when some female guests complained that an unidentified man had misbehaved with them. Falle went looking for the accused, who ran towards a construction site operated by Shraddha Developers. While chasing him, Falle stepped onto a flimsy covering of wooden planks and steel sheets placed over a 35-foot-deep STP pit and fell in, police said. Soon after, at least 10 others, identified as Shreyas Surve, Aniket Kadam, Jaideep Shah, Sanket Juwatkar, Aditya Aaher, Aniket Patil, Ankit Rohit, Jaywant Farsane, Raman Yadav and Harishankar Karva, rushed to rescue him but also stepped onto the unstable covering and fell into the water-filled pit. Fire brigade personnel rescued all of them and rushed the injured to hospitals in Mulund and Bhandup. While eight were discharged after treatment, two were admitted. However, Falle later succumbed to his injuries. Bhandup police have registered a case against executives of Shraddha Developers under sections 106 (causing death by negligence), 125 (acting rashly or negligently as to endanger human life or the personal safety of others) and 290 (negligent conduct during building construction or demolition) of the Bhartiya Nyay Sanhita. No arrests have been made so far....