Did Maedhros kill Laughter?

[Nerwen]

Originally Posted by Urwen

Accidentally stepping on bugs. Unlike Maedhros, she never stepped on heads, nor caused blood of Tuor and her other kinsmen to flow down the landscape of Dor-Lomin!

Well, exactly. Maedhros ends up having quite enough terrible deeds to his name without you throwing in extremely indirect and dubious stuff like that.

And you see, Urwen, about the bugs Lalaith stepped on– I happen to know one of them was a butterfly. Had that butterfly only lived, many insect-generations later one of its remote descendants would have flittered in front of Nienor's eyes and distracted her from being hypnotised by Glaurung.

There you have it: the incest and suicide of her brother and sister are clearly all Lalaith's fault.

I rest my case.