Filling in the blanks we have
As to who started it:
It was always burning, since the world was turning. So certainly not started by us.
And to spell it out explicitly
The sequence of images is enumerated in the lyrics of the popular Billy Joel song, "We didn't start the fire." The lyrics also explicitly say who started it (no one, it was always burning) and who didn't (we didn't) http://www.azlyrics.com/lyrics/billyjoel/wedidntstartthefire.html