Mani, along with his wife Arzu Moni, was killed during the Assassination of Sheikh Mujibur Rahman in a military coup on 15 August 1975. He lived two kilometers away from Mujibur in Dhanmondi. The attack on his house was witnessed by Mahfuz Anam, who is the editor as well as the publisher of "The Daily Star", whose house was on the opposite side of the lake from Mani's house. His two sons - Fazle Noor Taposh, now the mayor of Dhaka South City Corporation, and Sheikh Fazle Shams Parash, an academician by profession - survived the attack, as they were hiding under a bed. His wife, who was thought to be pregnant, was also killed.