the poor souls that lost thrie lives by being burned alive were most likely the victims of a firestorm. The wind will have whipped up the fire and the massive amount of heat consumes oxygen and sucks air into it, creating a tornado effect and the victims wouldn't have been able to out-run it. They may have suffocated before being burned up.
This phenomenon was first noted in the bombing raids on Dresden in WW2.
https://en.wikipedia.org/wiki/Firestorm