One person was killed and 31 others injured following a carbon monoxide gas leak in a steel company in Harbin, capital of northeast China's Heilongjiang province, late Monday night, local authorities confirmed Tuesday. The leak happened at 9:30 p.m. in Acheng Iron & Steel Co., Ltd. in Acheng district, Xinhua quoted a spokesman for the district government as saying in a press release. The injured are receiving treatment in hospitals and one remained in critical conditions, the spokesman said. An investigation into the cause of the accident is underway, he added.