Two brothers died, while another man fell ill, on Monday after inhaling toxic gas from a septic tank in a house in Gautam Buddh Nagar district, police said.
According to an official, the incident occurred in Chotpur Colony under Sector 63 police station limits after one of the deceased, Chandrabhan (40), fell into a septic tank after its stone lid collapsed.
Raju, his brother, also jumped into the tank to save him, but both fell unconscious.
The official said when their neighbour Hemant Singh tried to enter the tank to help them, he too got affected by the poisonous gas and is presently undergoing treatment.
On receiving the information, the police reached the spot, cut the floor of the septic tank with a power tool and recovered the brothers, rushing them to the Noida district hospital, where doctors declared both of them dead.
The police said the bodies have been sent for postmortem examination and peace and order is being maintained at the spot.