Emergency crews were struggling Tuesday to rescue 18 coal miners trapped underground in eastern China following a collapse inside the shaft three days earlier.
Three miners were killed by falling rocks in Saturday's collapse in Shandong province that also destroyed part of a drainage tunnel.
State media showed ambulances standing by at the mine entrance and crews equipped with oxygen tanks heading underground.
More than 300 people were working inside the mine at the time of the collapse, and most were lifted to safety.
China long had the world's deadliest coal mines but safety has improved considerably with more modern equipment, better training and the closure of most of the smallest, most dangerous mines.
China is by far the world's largest coal consumer and the amount it mined last year increased about 3 percent in 2017. While some coal projects have been cancelled as China struggles to clear polluted skies, coal remains key to providing heat and powering the economy.