Broken-down bus that crashed in China mine was bought online Safety inspectors say the operators of China's largest silver mine bought a broken-down bus online, overloaded it with miners and operated it on a ramp that wasn't fit for transporting people, leading to fatal crash

BEIJING -- The operators of China's largest silver mine transported workers underground on a broken-down bus that was bought online, routinely overloaded and operating on ramp not intended for transporting people, safety officials said after the bus crashed, killing 21 miners and injuring 29.

The bus involved in Saturday morning's crash had not been inspected or registered and had a capacity of 30 passengers, 20 fewer than were on board, the head of the Emergency Management Ministry's department of safe production infrastructure, Pei Wentian, told state broadcaster CCTV.

Pei said the bus was operating in a mine tunnel on ramps not intended for transporting people, increasing the risk. He said mine operators had also been negligent in passing on responsibility for safety in the tunnel to subcontractors and that safety inspectors had failed to ensure required upgrades were implemented.

The brakes failed before the bus crashed into a protruding wall inside the tunnel at the mine operated by the Yinman Mining Co. in the Inner Mongolia region. Executives of the company have been placed under travel restrictions while the investigation is underway, though there has been no word yet of possible criminal charges.

The mine also produces lead and zinc.

Yinman is a subsidiary of Inner Mongolia Xingye Mining Co., Ltd. listed on China's Shenzhen Stock Exchange, and mines around 201 tons of silver annually, according to state media.

China is the world's third-largest producer of silver, producing 2,500 tons of the metal in 2017, a little more than twice what the U.S. produces.

Scores of Chinese miners die each year, largely in gas explosions, underground floods and collapses due to structural defects, although safety improvements, mine closures and a drop in demand for coal have dramatically reduced the number of deaths in recent years.

According to mine safety officials, the number of deaths in China's coal mines fell by 13.1 percent last year to 333 — an all-time low.