First off, I have to laugh

because as luck would have it I took the day off today. I planned on sleeping in, lounging in bed reading my book this morning before I got busy.
8:00 a.m. I woke up to a back-up beeping (big truck backing in next door Noisy Neighbors house) shortly followed by a crew of men talking loudly, a generator started, the sound of chain saws . . . so much for my quiet peaceful relaxing morning!
I know, I know! I can't complain about NN for this one. In the middle of the week, after 8am, it's just my darn fool luck that I chose this day to take off! How ironic is that? LOL!
On to my question:
NN has a huge (easily 3+ stories high), beautiful oak tree in her back yard. I went out on my patio to watch the tree trimmers for a while.
In all honesty, if you've ever watched tree trimmers or a huge tree cut down (I hope they're not cutting down the whole tree!) it is a beautiful orchestration. The "monkey man*" on the tree saws off the branch where the guy on the ground guides the branch down slowly with a rope that is looped on another branch and is tied around the branch being cut. I hope that made sense.
Apparently one of the loops didn't hold well for one of the larger branches and it fell on top of NNs garage. I would say that the branch was easily 8-10 inches round and about 6 foot long, dropping from maybe 20 feet. There was a loud crunch/crash sound. Then, a while later, another smaller (but sizable) branch fell on top of the garage.
I'm wondering if I should say something to NN or should I talk to NN's landlady about what I saw just in case there is structural damage to the garage? (The garage has a peak roof and the branch fell right on the peak if that makes any difference.)
It may be that no damage was done or maybe the Tree Trimmers will be honest and give a heads-up to the landlady.
What would you do?
*calling him monkey man because of the way he climbs around the tree, jumping from one branch to the other. It is amazing to watch.