Hello. I was reaching out to this form to see if they could help me with my tree as far providing some information. It gets pretty hot in the region of Southern California that I reside in. Recently the leaves of my tree have been falling off at a dramatic pace. I have tried to water it as well. I think it may be something else, as my neighbor also had the same problem. I have attached photos. Thank You Eurastus
Do you know what kind of tree it is? If not, any photos with flowers or fruits from a different time of year? That'll be the first step to assess what might be going on. If no other photos, I suggest taking a branch (with leaves) in to your local county extension to get it identified and see if there are reports of pathogens afflicting this locally.