HYDERABAD: Two daily wage labourers hired by Biochemical & Synthetic Products Private Ltd at Zimkalwada in Sanathnagar police station limits on Monday, to clean the manholes fell unconscious after inhaling poisonous gases and died while they were being shifted to a hospital, while another person who entered the manhole to rescue them is in critical condition. For the last 10 days, the works are being carried out in the company. At around 3.30pm, Alladi Ramarao (51) entered a manhole and fell unconscious. As there was no response from him, his nephew Alladi Seetharam (35) entered the manhole and he too fell unconscious. On noticing this, another worker S Narasimhulu entered the manhole to rescue the duo, but fell unconscious inside. On being informed, the management called the fire brigades to rescue the trio. When they were shifted to a hospital, doctors declared Ramarao and Seetharam as brought dead. Narasimhulu, still unconscious, said to be critical.