Are we wrong to insist our 28 year old son pay for this? ?

It's Property damage, if they were tenants anywhere else they would be responsible.  Consider increasing the rent as payment to repair the house if it comes out of your pocket, and if they don't comply ask them to leave.  You are responsible for yourself as is your grown ungrateful children.

No, you're not wrong to ask them to pay for the damages that they caused. You're doing them a favor by allowing them to live there, and the fact that they are trying to guilt trip you and your husband into paying for their mistake is beyond ridiculous. I would seriously consider evicting them. I know it's your son and his wife but they've made it perfectly clear that they have no respect for you or your husband. If I had been foolish enough to cause damage to my parents home after they were generous enough to let me live there at a very deep discount then I would find a way to make it right. If they don't have the money to fix this mistake, what's next? They flood the house? Catch it on fire? It sounds like your son and his wife has a lot of growing up to do and if it were my son he wouldn't be doing it on my dime. 

I would absolutely make them pay!! It was THEIR FAULT. Landlords are NOT responsible for tenant idiocy or mis-adventure. That is a tenant's responsibility.


Why should you feel guilty?   You didn't do this--and you told him to hire a tree service. He didn't. He pays. 


And if he doesn't, take him to court. I don't know if I'd kick them out before giving them the opportunity to make this right--but if they didn't pay for the damage they caused, that would be the next step. 

time to move on with his life alone

Your son and his wife are IDIOTS!  Force them to pay for the roof and damage or MOVE OUT!!!!!!!!!!!!!!!!!!!!!!

 Your son and his wife should pay for it. It's not your problem if they have trouble paying for it. They damaged your property. Simple. You can cut them some slack on how long it takes for them to pay for it but set a date and be firm.

$500 a month for HOA fees and taxes?! is this a huge mansion or something?

OK, I think you are confused as the occupants of the house are related to you.  If the tenants (that's what they are) were NOT related to you, then this would be a very black and white situation.  As the owner of the property, it was up to you to arrange for the removal of a tree from that property.  You were obviously "OK" with the idea of the tree removal, as you suggested that your son should hire somebody to do it.  But really, it was YOUR responsibility to hire somebody to do the tree removal.  

SO, this situation started with your own negligence.  It was negligent to assign the task to your son.   If you want something done RIGHT...

Now, the tree falls on the house, which is an "improvement" upon the land that you own.  OK, that could have happened whether YOU (the owner of the land) hired a pro to remove the tree or left it up to your son to handle it.  EITHER way, you (the land owner) had to be prepared for the fact that shlt goes sideways.  Sometimes, trees fall.  They fall even if nobody is trying to knock them over at the time.  And sometimes when they fall, they damage things.  Like houses, for example.  

But that is what homeowner's insurance is for.  It's pretty clear that your son didn't intentionally drop a tree on your house.  But no matter who cut the tree down, it COULD have fallen on your house.  When a tree falls on your house, you file a claim against your homeowner's insurance.  That's what it's there for.  

Now, if you don't have homeowner's insurance, that would mean that you are an irresponsible homeowner.  And as the saying goes..."a lack of planning on your part does not make for an emergency on my part..."

To me, it sounds like you are trying to take advantage of your tenant, just because he's your son.  This is your responsibility.  If you don't like it, I guess you are free to evict your tenants.  But even if you do that, it is STILL your responsibility to remove the tree, and to pay for the damage to your own house.  Most people would just file the insurance claim, because they (duh) have homeowner's insurance for things like trees falling on the house...

Don't you have homeowners insurance?  Make him pay the deductible.

I think it's unlikely you would be classed as landlords and they tenants, and he is your son and you appear to have an informal financial arrangement with them. If they would like to go down that road, you could insist that from now on they pay the going rent and draw up a contract. Regarding the tree damage, of course they are at fault as they did something stupid ( may not be covered by insurance because of this?). I suggest you go up there to inspect the damage and get a couple of quotes for the repairs. Then you start negotiations for how the bill is paid. If they refuse to contribute to the cost, you could go the whole hog and take legal action but I guess you don't want to have to do that. Certainly getting into a huge argument could result in alienating your son and family, so if the relationship is valuable to you then you will want some kind of compromise. Personally, I wouldn't want to trust them with my property in the long term! Perhaps agree with them that they will find an alternative place to live in say 3 month's time