569 Raipur, April 18 Authorities have ordered an investigation after four coronavirus patients were killed in a fire at the intensive care unit of a private hospital in Chhattisgarh's Raipur city, police said on Sunday. Raipur Collector Bharathi Dasan has ordered an investigation into the incident. Officials have been directed to conduct safety check at all coronavirus hospitals in the city. The fire broke out at Raipur's Rajdhani hospital on Saturday, police said. "Four persons died in the incident, one from fire injuries and three due to suffocation," a police official said, adding a case of negligence will be registered against the owners of the hospital.