The main gas supply line to Narsingdi was damaged during construction work on a drain, according to Titas Gas authorities
The dead man was identified Md Rubel, 23, who worked in the MV Kirtonkhola-2 vessel which arrived in Dhaka from Barishal early Friday.
The incident occurred around 10:45 am while the launch was docked at the terminal's pontoon No. 1, said Sub-Inspector Enamul Haq of Sadarghat police outpost.
SI Enamul said, quoting launch staffers, the owner of the canteen 'Yamin' stabbed Rubel with a cleaver before boarding another launch to escape. Police are investigating the incident, he added.