I was thinking more in the initial stages. Obviously if the person is already "famous" and very well-known killing the person would be a bad decision, but if the person is not very well-known yet, then it seems much easier.

But yeah, does anyone really think they can manage to keep thousands of people quiet who were involved in it? I think that it is rather telling that the only people who argue about the physical impossibility of the crash and collapse, etc. are average joes who search wikipedia for their information, but actual physics, engineering, and demolition experts don't see physical impossibilities in it.