The sudden blast in the house at Liluah Bagan area of the town this morning also damaged the building and sent locals rushing out of their homes, police said.
Hoogly Superintendent of Police Tanmoy Raychowdhury said the tragedy was caused when a bag, which got exchanged in the train when the youth's family was returning from a trip to Gaya three days ago, suddenly exploded.
The family had gone to Gaya to attend a wedding but they had not complained either with the Railway police or the local police about the exchange of the bag, the SP said.
The house had been rented out to the family, which hails from Bihar, about four months ago. The youth worked at a clothes store in Kolkata, the houseowner said.