It's possible that your charger has simply stopped working, and your phone battery has died. Trying plugging the phone into a known working charger, with a known good cable. If all else fails, plug it into the USB port on a PC and wait a couple of minutes to see if the charging light comes on. I would keep an eye on it during this, just to make sure it doesn't do anything odd, like get unusually hot, just in case it is a problem with a defective battery.
It's also equally possible that it is simply be a defective unit.
Then, there's the "extreme" possibilities. Personally, I've had a similar situation because my apartment complex was struck by lightning. I woke up when the lightning struck, so I knew what happened, but it's not impossible that you got some kind of gigantic surge and didn't realize it.
I'm hoping it's just your charger.