Rescuers say they have nearly completed an escape tunnel for 33 miners trapped in a mine in Chile.
Engineers said they had just 2m (6ft) to drill to reach the miners 700m underground.
But Mining Minister Laurence Golborne warned that the rescuers had to work carefully not to jam the drill.
He also said that it would be three to eight days before the rescue mission at the San Jose mine would begin.
The miners were trapped in a chamber when part of the mine collapsed on 5 August.
The miners have now been underground longer than any other group.
Sirens and car horns
"We are very close," Mr Golborne said on Friday. "It would be very complicated if after all the work we have done... you lose the hole. We have to be very careful and do it in a controlled way".
Andre Sougarret, the engineer in charge of the drilling, said there were dangers that when "we break through the hard rock... someone might get injured".
"That's why we need to send a camera down the shaft to make sure they're not going to be in danger."
When the rescuers break through to the chamber where the miners are sheltering, they are expected to sound sirens and honk car horns to alert the miners' relatives.
Officials say the camera will then help determine if the miners could be winched up through the exposed rock, or if they would have to wait for the shaft to be encased with steel piping.
Mr Golborne said that a decision would be made on Saturday.
Huge cranes have been brought in to lower the metal casing if it is needed.
Officials say everything needed for the rescue is now in place.
It is expected to take an hour to winch each man to safety.
They will be given a pair of sunglasses to protect their eyes when they emerge into the sunlight.
Their relatives, many of whom have been camping at the site for the past two months, have been preparing a party to celebrate their rescue.
Hundreds of journalists from around the world are expected to cover the event.
The men were trapped by a rockfall at the gold and copper mine near Copiapo, about 725km (450 miles) north of the capital Santiago.