Kochi, Two migrant workers were killed, after gunpowder stored in a building at a private quarry in Malayatoor here was exploded early on Monday.The workers were accomodated in the building where the gunpowder was kept. The deceased hailed from Salem in Tamil Nadu, police sources said.The building was completely destroyed after the explosion.The bodies of Periyannan and Dhanapalan were kept in the mortuary at a private hospital in Angamaly.The cause of the explosion is not yet known and police and fire brigade officials rushed to the spot, Sources said.