I have a 2011 outback limited. This morning when I went to start it, I put the key in, everything lit up, the fuel pump kicked on and the fan kicked on. The car appeared to have full power in all key positions until I actually tried to start the car. Then all power cuts off: lights, fuel pump, fans, everything. And they stay off for about 5-10 minutes. They the whole thing resets and does the same thing again. And the ignition won't release my key whether it has power or not. Any clue what's going on?

Is it the original battery? It could be time for a new one.

Battery dead or corroded terminals.

If it's original battery, it is overdue by about 2 years.  Typical LA batteries have 5 year lifespan under ideal conditions.  Normal use in a car is not ideal conditions.

 

Or, it could just be dirty / corroded connections, or open circuit in the battery, or other main power feed.