Are you sure the leaves you show (Euonymus leaves) are on the trunk you show? That would be enormous for a euonymus which is typically a shrub.

Yes. That picture is from the branch I trimmed off.

Fringe Tree, Chionanthus virginicus.

That might be it. I can't remember exactly what it looks like in the spring when it flowers. U do remember it is white though. Any idea what would cause the trunk damage in the picture? It is completely hollow.

There is no way to know for certain what caused the original wound that led to the rot. At this point it doesn't matter much anyway. Life, it's messy and imperfect.

The tree still looks decent. We are putting in a pool and fence just inside where the tree is. Im just afraid its going to come down on my fence and into the pool.