Oh fer fuck's sake, not this shit again. The steel didn't go "poof" due to directed energy. The fire fueled by the aviation gas simply changed the temper of the steel. When steel is cast, it goes through a tempering (or quenching, or annealing) process that sets the internal crystalline structure of the steel to meet a desired load-bearing specification. The intense fire altered that crystalline structure, hence the steel lost its load-bearing capacity, and it simply failed. Nothing spooky happened.