HELP! Having issues with wiring...

[JThiessen]

So now that the pics show up (thanks BrianG!), thats the way I have it wired. When I connected the batteries, the black wire going into the UBEC is the one that fried. What could be the possible causes for this? I realize that potentialy having wires crossed or backwards may be one thing, and I'm going to have to take the time to go over every connection. But what I'm more concerned about is if the UBEC was damaged, and how to tell, or if the ESC was damaged, or if the reciever could be damaged (this last one may be a possibility. Since I'm only running two wires in, how do I determine the orientation of the plug where it plugs into the reciever? I used one of my other traxxas recievers that is connected as a go-by when I plugged it all in.