what in the world... plant has gone from large and flowering to completely dead..

this plant was doing very very well, i was thinking i would get near 100g of dried manicured buds from it.. due to my work schedule i hadnt been able to check on it as much, we started having a little gnat problem after spider mites on a previous plant, gf made a vinegar trap and a few days later i popped the room open and the whole plant was just brown and falling apart, this is after no new growth for a while. after taking all the death and decay off the plant i open it up again today to find this, literally the entire plant falling apart, very very brown and literally nothing usable at all left on it.

so let me ask this, WHAT IN THE WORLD HAPPENED< how can i make sure this NEVER happens again? i thought maybe at first it was that damn vinegar trap she put in there, but after removing it it looks like this.. what happened??!!

Looks like some major heat damage to me...... YIKES!!

yeah heat mate, the stems look ok.

why just this one plant and not the rest of them?

im guessing i should go ahead and chop it down...

what do the roots look like mate?

not really sure as im in soil, it doesnt feel weak or anything, it just seems that all the buds and such have completely died...