Ps3 turned off by itself?

ok i was playing ratchet and clank tools of destruction, i managed to play for around 1 hr and a half, and finished the game, went to challenge mode and bam the ps3 just shuts off and red lights started blinking, i turn it back on and it says i haven't turned off my ps3 correctly and may lose data etc, then i pressed the ps on and it shut off again, i turned it on again and it is fine for now, what is the problem? is my ps3 dying?