Experts say it may take up to four months to free 33 miners found alive after more than two weeks underground in a collapsed Chilean mine.
Reports from the San Esteban gold and copper mine near Copiapo in northern Chile say the massive rockfall that occurred on August 5 is still unstable, and there could be more collapses.
That complicates the rescue work, and mining experts say they will start drilling a new shaft in an area not affected by the rock movements.
Hope of finding any survivors was dwindling when a probe drill came back to the surface on August 22 carrying a note scrawled in red paint saying all 33 miners were safe and well, and had taken refuge in an emergency shelter.
Overjoyed relatives wept and sang as they heard the news from Chilean President Sebastian Pinera, who was at the mine.
"I want to say that today all of Chile is crying with happiness and emotion," Pinera said.
"The first thing I want to do is thank the miners for the strength, the valor, the courage of surviving more than two weeks, alone, in the depths of the mountain. Also, to thank the family members."
There was a second note that came to the surface with the same probe, a message from the oldest of the miners, 63-year-old Mario Gomez, to his wife Liliana. Gomez wrote that "God is great," and expressed confidence they will be safe.
His 28-year-old daughter Roxana was overjoyed.
"When [my father] comes out, I'll tell him a million times that I love him," she said. "A million times. Nobody would be able to take away the happiness that I feel right now."
Rescue Efforts Continue
Rescue workers at the drillhead sent a video camera down the narrow shaft, and it showed the trapped miners in apparently good health and smiling at the camera.
Food supplies in the shelter had allowed the miners to survive for 17 days, and Gomez wrote that they had dug a channel for water and used the batteries of a truck for light.
Plans are in hand to send mineral-enriched food and water and medicines down the tube, and also a cable to allow family members to communicate with the trapped men. Psychologists say such contacts will be important in sustaining the mental health of the trapped miners in the months ahead.
President Pinera has promised an overhaul of the regulations governing mining in Chile, which is the world's biggest copper producer, and a significant exporter of gold.
He has fired several officials connected with mining regulation. The privately owned San Esteban mine has reportedly seen a series of accidents in recent years, in which a total of 16 miners died.
compiled from agency reports