I know you weren't asking me, but...
The floors were 4" thick, so 10 stories worth of concrete would be ... 40 inches (a little over 3 feet), assuming that the concrete didn't pulverize to be even less thick. So what Doyle and Kirby observed (10 stories in 6 feet) seems reasonable. I'm sure that this has been covered here before a few times; maybe if someone was really interested in learning about it, they could use the search function.
How thick do you think each story was?
The floors were 4" thick, so 10 stories worth of concrete would be ... 40 inches (a little over 3 feet), assuming that the concrete didn't pulverize to be even less thick. So what Doyle and Kirby observed (10 stories in 6 feet) seems reasonable. I'm sure that this has been covered here before a few times; maybe if someone was really interested in learning about it, they could use the search function.