After the World Trade Center collapse , a glowing big hunk of supposed steel was seen among the wreckage. I don't recall how long it was glowing hot, but I seem to recall it was around 16 days. You can look it up. This kind of behavior is totally abnormal.
Like any occupied office building, lots of stuff was in it. Those would include laptop computers with lithium batteries, high nickel alloys such as from coffee pots or restaurant ware. Organic materials with hydrogen were plentiful from the aircraft fuel. Where to get free hydrogen and incorporate it into molten steel is a mystery. Hydrogen is the only missing ingredient for LENR and it might not have been missing.
It is usually not a good idea to put socially controversial subjects into a technical forum. I have done so anyway, because it plausibly could have been an example of LENR.
Everyone please comment, but let's avoid all the conspiracy stuff. Let's stick to the actual technical environment of the 9-11 event.