For say a child accidentally burns a hole in a new couch from something being knocked out of their hand, how much could they be prosecuted for if the destroyed item is worth $500.00 brand new?

I doubt they will be "prosecuted" but they along with their parents can be sued in civil court for the value of the couch up to the full replacement value. Or repair if possible.

So basically if sued, the mom or dad will write a check for damages since they are liable for the actions of their child.

Now so much can depend on how the accident happened.

And it sounds like someone else was the one at fault, who "knocked" this out of their hand, they may be the one who has to pay ? Or at least they may have to pay a percentage of damages

Is a minor responsible for accidental damage to personal property? Hello c:

It depends on the circumstances. As you describe them, I don't think the child or his parents would be held responsible.

excon