I had a fine stack, final table was near...but this hand destroyed all.

Found myself with JJ under the gun, was happy..but i blew it. No reads since I had just been moved to that table.

What did I do wrong? Should I've folded to the PF raise? I was re-raising to see where I stand, but I only got more confused and the flop was horrible.

PokerStars No-Limit Hold'em Tourney, Big Blind is t1200 (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

Hero (t24471)
MP (t15403)
CO (t28095)
Button (t23485)
SB (t26836)
BB (t34511)

Preflop: Hero is UTG with J, J.
Hero raises to t3600, 3 folds, SB raises to t6000, 1 fold, Hero raises to t8400, SB calls t2400.

Flop: (t17100) 8, 9, A (2 players)
SB checks, Hero bets t8400, SB raises to t18361, Hero folds.

Final Pot: t43861

Results in white below:
No showdown. SB wins t43861.

what is the point of your reraise?

with 20bbs and UTG 6 handed, I would have been all in - there is only about a 7% chance that anyone behind you has AA, KK, QQ. only an 18% chance of AK,AQ, or QQ+ so 4 out 5 times you pick up pick up the pot or have a chance to double up as a dominating favorite.

20bb is not a "fine stack"

By may calc, if the table will only call you with AQ+ or QQ+, pushing is +2200EV assuming an ante of 100. That is pretty damn good.

If you want to make it really tight and say they will only call with QQ+ and AKs, still +2100.

Push, don't donk around, you dont have enough chips to play poker.

Wow, this is a very interesting hand. Late in a tournament you put in a 3XBB raise from UTG...I have to put you on a good hand. Then SB RRs (reraises), but not significant. This is when I call and play JJ for the set value...and (only if I know my opponent) maybe as an overpair. I worry that his minimum RR represents a bigger hand.

BTW, I also often forget the odds that I am giving someone when I make a RR. I am trying to make my standard RR at least 3X the original raise...even when just trying to get information. Then a call really tells me something.

For me, when that Ace shows up I either push or check-fold to any bets. My concern is that if he has KK or QQ, he will only fold if you strongly represent the Ace. BUT, there is a decent chance that he has an A...possibly a set of them.

I would also want to know more about the money...are you in? How much do you jump up if you make the final table?

Personally, I don't like JJ OOP when someone puts in a reraise preflop. And I like it a whole lot less when an ace flops. So for me, I check-fold this one after the flop and look for another opportunity.

By this time into the tourney you should have a pretty good idea of what the fold threshold is for pf raises. Your pf raise of 3xBB is pretty standard for most positions but for UTG with JJ I want to either limp it in or bet the folding threshold (this may be 5xBB or higher depending on table) Limping is sneeky and cheap if you get to see the flop unraised plus it keeps the pot small and easier to get away from if necessary.
But a larger than standard opening bet can also save you a few chips since only very good hands will call/re-raise. Your re-raising the SB was pretty costly and represents AA, KK and maybe QQ but not something I would do with a JJ - that the SB called would have me very worried. This 3rd pf re-raise was more costly than a 5xBB 1st raise and anyone coming over top is pretty good indication you're behind. I'd have to give SB nothing less than AK unless your table image is fairly loose.
With that flop, I would have bet the SB check too and folded as you did but it probably would have cost me less. Had you limped and called a SB standard 3xBB raise the pot would have been only 4800 (3600+3600+BB) and your 1/2 pot bet only 2400 instead of 8400. Or had you pf raise 5xBB and were just called by SB (if he comes overtop 5xBB - you fold right?) the pot would have been 13200 (6000 + 6000 + BB) and a 1/2 pot bet would have been 6600 instead of 8400.
When blinds get this high, controling the pot size becomes extremely important and unless you are holding AA or KK, you should try keeping the pot smaller (even with raises) until you've seen the flop. It may seem odd that a 5xBB raise will keep the pot smaller than a 3xBB raise but it will if it discourages a re-raise or gives you a chance to get way from the had if it doesn't.
What do you think?

I forgot to say...NICE FOLD. I know it seems standard at this point for any decent poker player who is looking at the hand history...but so many players will become emotionally attached to their nice pocket pair and make this call. They tell themselves: "He has to be bluffing." or "Look a backdoor straight draw!"

So, even though it seems obvious...your fold shows that you can make a logical, non-emotional play with a very tempting pot in front of you. IMO, that puts you in a minority.