Two people were killed and 13 injured — including one man who remains in critical condition with third-degree burns on 99 percent of his body — after molten iron spilled from a refining furnace at a steel plant in Shanghai on Monday.

Officials at the plant, owned by Baosteel Group Corp, China's largest listed steelmaker, said the accident happened around 9:10 am when workers were clearing molten slag from the furnace.

According to a preliminary investigation by the Shanghai Administration of Work Safety, a hook lifting the furnace failed, toppling the 270-ton structure.

The injured workers were taken to No 3 People's Hospital, which is affiliated with Shanghai Jiao Tong University School of Medicine.

In addition to the worker in critical condition, doctors said six others were seriously burnt, and two of them with burns on 8 percent of their bodies.

Baosteel announced the accident on its micro blog without giving further details.

The Shanghai Administration of Work Safety said on its micro blog that it sent an investigating team to the site. That team included its own officials and representatives from the police, labor union, and Baoshan district government.

Liu Yanqi, an analyst specialized in the iron and steel industry at Haitong Securities in Shanghai, said the accident was Baosteel's "most serious work safety accident so far this year".

"But it will take the corporation some time for site clearance, maintenance and thorough safety inspection.

"Related furnaces will work on shifts, which is estimated to cut production capacity by 20,000 tons of crude steel a day."

The incident is Baosteel's third serious accident this year.

In July, a heat-supply vehicle at Baosteel Development Co in Shanghai exploded next to the canteen of a residential block, killing one person and seriously burning another.

In February, at its Meishan Steel Plant in East China's Jiangsu province, six workers were killed and three critically injured after a gas explosion.

The accident on Monday comes less than a week after the Shanghai Administration of Work Safety released new guidelines on how major industrial organizations should report and handle severe incidents, in which it urged accident investigation authorities to complete all investigative and supervision work within 60 days of any incident.

Under the Regulations on Accident Reporting and Investigation of China, which took effect on June 1, 2007, an accident that causes fewer than three deaths and fewer than 10 people to be seriously injured, or has direct economic effect worth less than 10 million yuan ($1.6 million) is classified as a normal industrial accident.

If the death toll is between three and 10, it is classified as a severe accident.

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