Gfci ......

[Cal_stir]

that damage to the plug and power bar was caused by current arcing across the terminals, hot and common, it probably only took a few amps to cause that damage which is why the breaker didn't trip, fortunately some current also arced to the ground terminal on your power bar, causing current to bypass the common terminal on your gfi causing it to trip. that is why it is so important to not get water on your electrical circuits.