At least one worker was killed while 15 others sustained critical injuries in an explosion in a steel plant in India's eastern state of Odisha, police said Wednesday. Police said the incident happened in Dhenkanal district of Odisha at around 10 am when many workers were working in the Bhushan Steel Limited plant and suddenly blast occurred in its newly-built second furnace. Soon after the incident, the fire engulfed the factory and fire tenders were rushed to the spot for dousing the raging flames, police added. They informed that the relief efforts were in full swing and dead and injured persons were being rescued from the incident site, adding, many people are still trapped inside the building and real numbers of casualties can be ascertained when the fire would brought into control. The police and state administration officials have reached the spot and a probe has been ordered into the incident.