indoor orange tree
I was away for 8 days but watered my tree well before I left. When I returned the leaves of the tree started to fall and have lost about half of its leaves now. Is this a natural fall happening or is the tree dying?
What you describe is not natural, but normally would indicate a water deficit (drought stress) or toxic reaction to alchohol or a chemical in the soil, or a toxic foliar spray of some kind.
Water deficit is the most likely, but I am surprised that the plant couldn't go one week without wilting and dropping leaves. Was it real hot in the house, is the pot very small, or does the soil drain very fast and not retain soil moisture?