Two siblings died reportedly after inhaling toxic gas accumulated inside a septic tank of an under-construction building at Hajiganj Bazar in Haziganj upazila of Chandpur district on Tuesday. The deceased were identified as Rabbani, 38 and Mohon, 22- two sons of Sajeman Ali of Nachole upazila in Chapainawabganj district. Also read: Madrasa girl ‘kills self’ in Chandpur Zobair Syed, officer-in-charge of Hajiganj Police Station, said the two brothers went to clean a septic tank in an under-construction building in the area around 9:30 am. Mohon first climbed down the septic tank. When no response came from Mohon after a long time, Rabbani then got into the septic tank. As he didn’t come out, local people informed the matter to local Fire Service men who rescued them. Also read: Seeing elder brother’s body, man dies in Chandpur Later, they were taken to Hajiganj Upazila Health Complex where doctors declared them dead.