<p>I was working on my printer when something metallic came into contact with the pcb. I smelled smoke and quickly unplugged the printer. Anyway, this is the result and, of course, the heat bed won't heat. </p>

<p>Can this be salvaged or should I toss it and buy a new one? </p>

<p><a href="https://i.stack.imgur.com/WhRPu.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/WhRPu.jpg" alt="shorted"></a></p>

<p><strong>update</strong> the heat bed was not hot at the time. I had the heat bed unscrewed from the chassis but had forgotten to unplug the printer. I am not exactly sure how it shorted but I think it shorted between the power lead connection and the thermistor. </p>

What happend was short circuit of course. There is no doubt you overheated HB so copper detached from HB base plate. Because you wrote it doesn't work it means copper tracks are broken.
There is very low chance to fix it. I mean it - near to zero.
What you could do is:
Detach HB from arduino
Find a place where track is broken (which needs to uncover it from protective layer)
Connect it with a wire
Unfortunately even if you do it and your HB will work (electrically) your fixed HB which won't be flat anymore.
So definitely it's to be thrown away.
[edit]
I just realised you have double power HB, which means your HB has 2 heaters... which gives a bit hope.
take a look here
here is schematics
which could give you an idea
You could check if your second heater works ok
If yes then you are salvaged! :)
[edit2]
I really suppose the schematics of HB is more or less like this
So if H1 is broken there is a chance to use H2 connecting pins respectively