Bhubaneswar: Four workers suffered critical burn injuries after a massive fire broke out at an under-construction ethanol plant at Nuagaon in Nayagarh district late on Wednesday night.The injured were identified as Dilip Nayak of Godipathar, Sarat Sahoo of Mahipathar, and Bibhuti Pradhan and Braja Kishore Pradhan of Kanigiri village. Sources said all four suffered more than 50% burn injuries in the incident.Preliminary information said workers were engaged in boiler-related work at the project site when the blaze erupted suddenly. The exact cause of the fire was yet to be ascertained.Following the incident, local fire services personnel rushed to the spot and launched firefighting operations. The blaze was contained in an hour, preventing it from spreading further within the under-construction facility.The injured workers were initially admitted to Nayagarh district headquarters hospital for emergency treatment. However, considering the severity of their injuries, they were later shifted to a private hospital in Bhubaneswar for advanced medical care.“We received four workers with serious burn injuries. Necessary treatment was provided immediately. As their condition deteriorated, they were referred to a higher medical facility in Bhubaneswar,” said a medical attendant at Nayagarh DHH.Police said a case has been registered and investigation is underway to determine the cause of the fire. “Condition of all four injured persons remains critical. They are currently under observation at a hospital in Bhubaneswar,” a police officer said.