Do you know which wire it is that touched the metal?
You might of blown the amp inside the deck.
To see if the speakers are "dead" use a battery to test it.

This is a polarity test, but you can use it to see if your speakers are fried or not. It should make a "popping" sound when you touch the wires together. If you hear nothing, they are toasted. I would do this from the car harness itself before you connect them to the deck.
If you don't hear anything, I would do it again, but this time pull out the speakers and wire it directly to the battery. If still nothing, the speakers are shot. If you get something, you have a bad wire somewhere in the harness.