industry coming in and offering help and advice, it is just incredible. it makes me feel exhausted just thinking about what's being done. >> are there lessons learned from this, dave? are there going to be thing in mining around the world that change because of this? >> i would predict that there will be two or three very important changes. until the whole experience has been analyzed, we won't know exactly which the most important thing are. but there is obviously the fact the men have survived for 69 days. that's unprecedented. three week it was maximum at this point. in china, the drilling, the shaft, the only precedent for that was the rescue of nine coal miners in america in 2002. but they were only 70 meters underground. that's another first. they have blazed a trail, this group of rescuers and this group