Reno, Nevada: A man has died after falling into a mine shaft so deep and treacherous that rescuers had to abandon efforts to reach him while he was still alive, officials said Saturday.

Devin Westenskow, 28, worked at a geothermal drilling operation in Nevada and had gone exploring on Wednesday with two friends during his off-hours when he fell 58 metres into the open shaft northeast of Reno, authorities said. His family thanked rescue workers in a statement.

Instability

"We feel they did everything possible to rescue Devin, but that there was no way to get him out alive given the extent of his injuries and instability of the mine shaft," the statement said.

"We are forever grateful for their efforts." The decision to end the rescue came after two unsuccessful attempts by search teams to descend into the shaft, where Westenskow was trapped in debris, said Doran Sanchez, a US Bureau of Land Management spokesman.

An attempt Thursday caused walls of the 100-plus-year-old shaft to crumble and rocks to fall on rescuers, he said.