The miners trapped almost a mile deep in a collapsed copper and gold mine saw tangible evidence that their rescue grows closer today. The “Plan B” drill broke through to the cavern where the miners have been awaiting rescue for the last 66 days.

But obstacles and dangers still lurk within the difficult, and untested, rescue plan. Before any of the miners can be brought to the surface, rescuers will carefully inspect the 28 inch wide shaft that now goes all the way down to the miners. The shaft is almost as long as 7 NFL regulation football fields, laid end to end, but vertical.

The shaft will undergo an intense video examination prior to the next step. Then a decision will be made on whether or not to reinforce the shaft. Reinforcing would entail the installation of a steel tube into the shaft, to prevent rocks from falling, or the sides of the shaft from crumbling, as the miners are brought out. The rocks or crumbing could jam the small cage, or ‘capsule’, that the miners will use to ride up to the surface.

However, installation of the tube, which weighs 150 tons if installed through the entire length of the shaft, could take weeks. Time in which the miners could face other dangers inside the unstable mine. Another installation risk would be the possibility of damage to the shaft, or adding the the instability of the site, during the installation process. “It’s not an decision easy to make,” said Chile’s Minister of Mining.

If the decision is made to continue the rescue without installing the steel tube, the 33 miners could begin to be brought up to the surface early next week. The ride to the surface will be harrowing. One miner at a time will need to stand, in very cramped quarters, as they are pulled up through the narrow shaft in a tiny capsule designed specifically for this rescue. The miners have been undergoing physical and mental training to prepare them for the journey out of the mine.

After making it the surface, the miners will be taken to a field hospital, allowed to meet with a small number of their loved ones, and then taken to a hospital for observation and medical care.