Four labourers were killed and another was rescued after they fell unconscious while cleaning a tank in a factory located on the outskirts of the city.According to the Chhipa Welfare Association, four labourers, identified as Zahoor, Tanvir, Faizan and Faisal, were recovered from a tank in a factory in Ghaghar Phatak.The labourers were declared dead at the site and were shifted to Jinnah Postgraduate Medical Centre (JPMC), a spokesperson for the organisation said, adding that another labourer, whose identity was not immediately ascertained, was rescued from the same tank.Bin Qasim Town police station SHO Dhani Bux said that the factory management had hired five daily wage workers to clean the tank and during the work they were found unconscious. He added that the factory produced chemicals and was also under construction.The JPMC executive director, Dr Seemin Jamali, confirmed receiving four dead bodies at the hospital’s mortuary, which were later handed over to the families after initial medico-legal formalities were completed. They apparently died of the asphyxia, she said.The police say that a case will be lodged after the families approach them. “We have started conducting the investigation and will register a case as and when some evidence about someone’s alleged involvement or negligence surfaces,” SHO Bux said.National Trade Unions Federation, Pakistan Deputy Secretary-General Nasir Mansoor said that the incident bespoke of the apathy of the authorities towards labourers. “It is a case of zero implementation of health and safety measures at workplaces. It is said to be a chemical factory. In this case, there is a specific code that [tells you how to] clean chemical tanks,” he said.The responsibility lies on the shoulders of the labour department and the factory management, he said, adding that unfortunately neither of them seem to be concerned about health and safety of workers. “In the factories on the outskirts of the city the situation has gotten worse,” added Mansoor.Earlier, in October last year, three labourers were killed in a similar incident as they fell into a 25 to 30 foot deep chemical tank of Indigo Textile Mills located in the same vicinity.