Two workers died apparently after inhaling toxic gas from a septic tank at a house in Bera Upazila of Pabna district on Thursday.
The deceased were Sajibul Islam, 25, son of Abul Kalam and Mostakin, 30, son of Abdul Gafur of Hatigara of Bera municipality area.
Waliur Rahman, officer-in-charge of Bera Model Police Station, said the septic tank was constructed in the house of Taher Uddin 10/12 days ago.
On Thursday morning, when workers were opening the bamboo mould of the septic tank used during the construction of the roof four workers fell unconscious.
Hearing screams, local people rushed in and took them to Bera Upazila Health Complex where doctors declared two of them dead.
Rabiul Islam and Samrat Sheikh were taken to Pabna General Hospital.
Doctors said lack of oxygen inside the septic tank might be the reason behind the death.