Maybe not “on the hook,” but it’s probable that the couple could sue them for recovery of damages. The parents will probably hire a lawyer who will try to make a case for the fact that this wasn’t foreseeable, and the children were properly supervised for their age. If this is the first time the children have done anything remotely like this (as far as anyone knows) and their parents, or someone their parents designated, was home, and a few blocks away, the couple could lose.
When I had homeowner’s insurance, my agent made it very clear that there were two kinds of policies: one was the minimum required by my mortgage lender that insured the building for damage, and the other that covered the building, and also covered the contents. I remember very specifically a discussion of where my bicycle had to be, and how it had to be secured in order to be covered.
It was a small house, and the insurance for the house was about $80/month. It was about $20 more to cover the contents, and that included large appliances.
I’m not suggesting that these people deserve what they got, nor that they don’t deserve any help they get now-- this is awful, and yes, it’s terrible that the law does not have some way of seeing to it that the children can’t at the very least get suspended sentences or be placed on probation through, say, age 16.
That way, nothing happens to them now, in case this earlier behavior was simply an aberration, or misunderstanding, or result of a poorly developed thought processes. But if they do something again when they are older, and it turns out this was the beginning of a pattern, then at that point, they can receive harsher sentences as predicate offenders. And that second offense could be anything, including being caught with cigarettes underage, which means they will spend their childhoods looking over their shoulders.
However, I find it hard to believe that the couple didn’t have the option of buying insurance that covered the contents of their house, or that people with a hot tub and multiple TVs could not afford this.
That said, I hope their parents ground them, take away dessert, and their allowances, until they are 30. Also, that they have to help with the clean-up.