the miners began doing the chile chant, the chi-chi-chi chant. and one of them picked it up and chanted it back to them. and it was quite impressive show. >> larry: what would you say is the biggest medical concern? >> there are multiple. certainly myself and my chilean medical colleagues are not going to breathe deeply until they are all safely out from the mine. but it ranges from engineering failures to rock collapse or low blood pressure in the miners as they ascend and folks who lock their knees when they stand up straight at attention. there is a myriad of things that the chileans have practiced for,