PC Shutting Off Randomly


My PC is shutting off randomly, and there are no signs leading to this problem. I know for a fact that the CPU and GPU are not overheating, and I would think if it was it would have happened before this, because I have had my current CPU and GPU for a year or so. It seems to crash only when playing a certain game, but it seems odd that it would cause a total shutdown and not a blue-screen or something else, I think it may somehow be the Power Supply, but I am not entirely sure. My specs are below.

CPU: AMD Black Edition FX-8350 Octa-Core @ 4Ghz
GPU: MSI GeForce GTX 970 Dual Frozr 4GB Gaming Edition
RAM: Corsair DDR3 @ 1066 Mhz, 10GB
Motherboard: Asus M5A99fx Pro R2.0
Power Supply: Thermaltake TR2 500W