Premier Li Keqiang talks to miners before entering the 300-meter-deep Guandi Coal Mine in Taiyuan, Shanxi province. He praised their hard work, saying the miners are "not only the backbone of Shanxi, but also the backbone of China". Li had an inspection tour in Taiyuan, capital of North China's Shanxi province on Jan 4-5. [Photo/Chinanews Service]

When 33-year-old Shi Haiqing answered the phone in the safety center at a coal mine in Taiyuan early on Tuesday, he thought the call might be from one of his colleagues reporting on work safety.

But the caller asked: "Can you tell me about the gas density at the position where I am standing now? Can you tell where I am at the moment?"

Shi felt the voice sounded familiar, but lost no time in replying. Taking a glance at the control panel, he said, "The gas density is 0.05 (percent per cubic meter)."

His heart then pounded with excitement after the caller told him, "This is Li Keqiang."