Was it topped by a storm at some point? I’m having a hard time following the trunk up to the top. How about a pic further back with the lean going across the field of view instead of away from the camera.

tj

I can't tell where the hollow is. Is it at the base?

I’m thinking the video is looking up from the base but if the tree was topped in a storm the rot may go all the way up.

tj

Thank you for replies. I'm not sure if/when is was topped by a storm. Here is the new photo.

Thanx for the pic. The tree looks fine up top so the question is how bad/extensive is the rot below. Without probing around in there not sure anyone can tell from here. You may need an arborist to look at it.

tj

Thank you.

It is better to contact a specialist to look at it. The safety comes first, but I hope you can save it. A beautiful tree like this takes a long time to grow.