Gurugram, Aug 3 : Four workers were killed while another injured in a tragic accident while fixing a tower crane to the 17th floor at the construction site located in Sector-77 of Gurugram on Tuesday evening, officials said. The incident took place at around 5 p.m. at an under-construction site of Emaar Plam Hills in Sector-77 where a residential project is coming up. Of the five victims, four died on the spot while one was hospitalised in a critical condition. All the victims were natives of Bihar, the police said. "The accident occurred after the the victims were fixing tower crane used to transport construction materials atop the housing project with the 17th floor and they slipped. All five fallen from the 17th floor one of them was stuck on the 12th floor's safety equipment who is injured and undergoing treatment while remaining have died," Suresh Kumar, assistant commissioner of police (ACP), Manesar said. Kumar said that prima facie "we found that required safety equipment which was installed on the 12th floor by the contractor was not enough. A detailed investigation into the matter will be carried out". Further details of the victims are yet to be established, the police said. "Duty Magistrate and a scene of crime team will soon visit the site and after a detail probe, FIR will be registered against the concern persons of the project as per the prescribe law," Kumar added. The bodies of the victims were placed in the civil hospital. According to the police the contract of the project was given to a JJRS contractor. /IANS