"Burn baby burn" was the chant of angry rioters in the Black ghettos of America during the notorious urban riots of the Sixties only a few years before the song came out..
Then in the same mid seventies era of the song there was a fad in Hollywood of 'disaster movies'. One of these disaster movies was "towering inferno" about a sky scraper on fire. Kinda like the real 9-11 (now that I think about it).
So those are the references being made in the lyrics..."a hundred stories tall", and "burn baby burn".
Hard to believe that a song in my lifetime now has to be dissected like a line of Shakespeare.