But feel free to believe anything that reinforces your existing beliefs.

1. Turn off comments

2. Turn off comments and hide all comments to date.

You can't have it electing to remove one comment or another. At most it could delete a top level comment that was the spawn of the flamewar. But still, I say hide all comments and turn off further comments. That way we still get the benefit of the story.

A few days ago, on the topic of turning off comments when there is a flamewar, instead of knocking the entire post down/off the front page, I said this:

"[killing the discussion entirely] is a good thing, if something is on the front page then comments should be enabled, if only in case something in the article desperately needs to be corrected. If we get a post on here about a new study suggesting that vaccines may cause autism, that would almost certainly generate a flamewar but the absolute last thing we would want is for the post to remain on the front page and not permit anyone to post comments that may refute claims made by the study. In situations like those, it is better to kill the discussion and to take the post off the frontpage than to leave it there but disable commenting."