The incident took place in Shil Daighar area.
Two workers of a motor garage were pushing a welding gas cylinder with their legs on the road when all of a sudden it exploded, Santosh Kadam, Chief of Disaster Control Cell at Thane Municipal Corporation, said.
In the blast, one of the workers, Samsher Alam Ali Shaikh (20), a resident of Thakur Pada, died, while the other Sejad Shaikh (25) was badly injured.
Two pedestrians, Abdul Hakim (66) and Rana Yadav (42) were injured in the freak mishap. The injured have been admitted to the hospital, he said.