Well done, brother! Those hollow ones can be tricky and totally unpredictable! Looks like a big silver maple?
Yes. It is amazing how young they can be and still survive. However, these did not survive and not many do around here... They are so thick they are pests.
Well done, brother. Glad you were able to help your neighbor and did it safely. Those hollows can be rough. Had a few lately my self. This is one of them, started making first cut, found the nice rock in the hollow
This was another concern. Some people fill hollow spots with concrete. I was able to see down far enough to make me confident I wouldn’t kill a chain.