Unfortunately you have been hit with either a power surge, or, even worse, a brown-out type of power issue that involves your power going too low to sustain your pc. Either one of these can and will cause extensive damage to any or all of your pc parts.
The problem is that the power coming into our homes is built on a power grid that is not set to pc requirements as pcs werent around when home power was created. So it doesnt really matter where you live. It happens to be a bit worse in my area of my city and a bit better in other parts of my city, but its always questionable. Im not an electrician so my report here, while it may not be totally correct, is correct enough to report the problem you have encountered, its just laymans terms.
That is why there are UPS's (uninterruptible power supplies) at the computer stores. I used to think they were extras that arent really needed, but i was wrong. These units condition the power and they dont allow power surges and they increase the power if and when it gets too low for our pc to run properly. They are very cheap these days and we should all have one. It happened to me once, lost my mobo, hard drive, power supply, video card,etc. Then i found out all i could about UPS's and i have 3 of them now and i dont have that problem anymore!
Unfortunately that is where you are, you have been hit bad. You need to get a UPS for the future.
Right now you have to take your entire pc apart and have each part tested
as that is the only way you will find out which is burnt out and which isnt.
Almost for sure you power supply is gone and likely your hard drive but you have to test them in other pc's to find out, or have them tested by a shop.
When you but a new power supply make sure its a good one. A good power supply has electronics inside it that will know what is going on and take steps to make sure your pc doesnt get the brunt of the problem and it will sacrifice itself to save your pc parts. A cheap power supply doesnt have that circuitry inside it to save your pc from harm! There is more than one reason to get a good power supply!
Im sorry to have to tell you all this by the way, but someone has to tell you.
It sure seems that this is the problem, based on the fact that you said that a power outtage hit your home. Its pretty certain that what i have said above is correct.