A 22-year-old labourer died after being exposed to toxic gas inside a sewage tank at the sewage treatment plant (STP) in Gangwa village of Hisar district, police said.Police said a case has been registered based on the statements of the victim’s family. (HT Photo for representation)The deceased, identified as Monu Kumar, was a resident of the same village. However, another labourer Sonu was also admitted at a private hospital after being exposed to the toxic gas. Officials said his condition is said to be stable.According to the police, the incident took place on Wednesday, following disruptions in the water supply plant, prompting two workers to enter the sewage tank to clear a blocked pipeline.While trying to remove the obstruction using an iron rod, the pipeline suddenly opened, releasing a large amount of toxic gas that had accumulated inside the tank. Both workers fell unconscious and were taken out of the tank by locals. Monu was declared dead at the spot due to suffocation, while Sonu was rushed to a private hospital.The family of the deceased has accused the plant management of gross negligence, alleging that the workers were “sent inside the tank without any safety equipment such as gas masks, oxygen cylinders, or safety harnesses”. They have demanded that a case of culpable homicide be registered against the responsible officials and contractors, along with adequate compensation and a government job for the victim’s family.Following the incident, police reached the spot and sent Monu’s body for post-mortem at the civil hospital. Police said a case has been registered based on the statements of the victim’s family. They said further action will be taken after the post-mortem report. Hisar superintendent of police Siddhant Jain said that the police investigation is going on and an FIR will be registered as per the statement and complaint filed by family members.