getting some crucial reinforcement, and engineers are testing everything out before the most complicated part begins, the actual rescue. seth doane is at the san jose mine tonight. seth, good evening. reporter: good evening, russ. mine officials have been very clear with us, pointing out, almost emphasizing that the risk involved with this rescue operation is still far from over. and late last night engineers here made the difficult decision of determining just how much of that rescue shaft to line with a protective casing. these giant pieces of steel casing were hoisted into position. they re being welded together and lowered into the rescue shaft to reinforce the walls. the process should take about a day and a half. here s how it works: rescuers are inserting 16 metal tubes, each about the length of a school bus, into the first 315 feet of tunnel. that part of the rock is the most jagged and unstable. then there s a slight bend in the shaft before it turns into harder ro
the surface by wednesday. this morning crews expect to reinforce the shaft with metal tubes. it could take up to two days to hoistall miners to the surface and chilean officials said all the miners are volunteering to be the last man out. seth doane in chile with the latest. reporter: the giant pieces of steel casing were hoisted into position. they re being welded together and lowered into the rescue shaft to reinforce the walls. the process should take about a day and a half. you can see some small fractures. and in order to prevent any contingency due to that, we are doing it in the first 100 meters. reporter: rescuers are inserting 16 metal tubes, each about the length of a school bus into the first 315 feet of tunnel. that part of the rock is the most jagged and unstable. then, there s a slight bend in the shaft before it turns into harder roshg for the rest of the descent into the mine. in copiaopo, the talk at the sunday market is about the rescue sglornts it hit