He is cutting through 9 inches of concrete? I can't even begin to imagine the difficulty of doing so. This reminds me of certain places in Asia where the buildings are solid concrete. The fact that they have to do this in order to provide plumbing and other features needed in a home is really impressive. http://talonconcretecutting.ca/core_drilling.html
I can't believe he is cutting through nine inches of concrete! My neighbor works on a core drilling team, and I always wondered what he did. This is a lot more interesting than what I had imagined. I have to get him to give me a demonstration.
