The countdown has begun to what’s being described as the riskiest phase of the plan to rescue Chile’s 33 trapped miners.
Engineers are reinforcing the first 100 metres of the escape shaft with metal tubing through which the men one-by-one will be brought to the surface.
But anxious relatives know the route to safety is still fraught with danger.
The drill hole is far from straight in fact it has several kinks which could catch on the narrow capsule which will be lowered to bring the men up.
Once the shaft has been strengthened the government expects to start the evacuation on Wednesday. It could take up to one hour for each man to be rescued.
Nothing is being left to chance as engineers practice using the cage – dubbed the Phoenix – in one of the most complex rescue efforts in mining history.