A steam sphere tank was found to be leaking, but production was not halted, ultimately leading to a January explosion at a steel plant in the Inner Mongolia autonomous region that left 10 people dead and 84 injured, an official said on Friday.

Li Haowen, head of investigation and statistics at the Ministry of Emergency Management, disclosed details of the cause at a news briefing in Beijing.

The blast happened at the plant, operated by Baogang United Steel in Baotou, after the tank continued leaking heavily for about an hour and a half before the incident, according to him.

"However, in order not to stop production, two on-site supervisors sent by the company still forced the work to continue," Li said.

"As a result, personnel working at the site, including the two supervisors, were killed."

"The supervision was not done properly. It harmed others and also harmed the supervisors," he said.

Li said China's overall workplace safety situation remained generally stable in 2025, with major accidents kept to single digits, while he stressed that "the lessons are extremely painful," reflecting the nine major accidents that occurred, as well as some typical cases since last year.

He noted that some companies failed to do basic work well, rushed schedules blindly, and engaged in corner-cutting, falsification, and other misconduct.

For example, the collapse of the Hongqi Bridge section of the highway in Maerkang city in Sichuan province in November revealed that the surveying company involved had not completed the number of boreholes required by the design, Li said.

However, the company falsely reported that it had, planting major hidden risks at the source, the official said.

These cases show that high-quality development must be built on the foundation of high-level safety, he noted.