No, maybe if thats the line then it should be Feanor and his son Maehdros who was rescued by fingon, fingolfins son. Handing him the high-kingship of the noldor in the process. The unstoppable flame would therefore be the silmarils that burned any evil that touched them. The jewels that also led to the kinstrife wars in the first-place and the madness of feanor. What men if the answer be that might be Noldor or Noldo Elves.
Of course the Unstoppable Flame might also be the flame of Arnor, the Secret Fire etc. but Id lean towards the kinslayings or the Men of Dale personally.