Joe Cassaligi Says: 'The Building Collapsed To Dust' -- Is He Crazy?

In the two-minute video, "9/11: Does this look like 'structural failure' to you?", NYC firefighter Joe Cassaligi of Engine 7 says:

You have two hundred-and-ten-story office buildings. You don't find a desk. You don't find a chair. You don't find a telephone, a computer. The biggest piece of a telephone I found was half of a keypad... The building collapsed to dust.

Is Joe Cassaligi crazy? Watch this video and decide for yourself.