Uma, From what you've said, my first suspicion would be root damage/loss. It would seem the roots can no longer support the tall tops. I'd cut the tops back hard and hope for the best.
Good Luck.

Uma

Check the center of the limb, where you cut, for frass... it will resemble a powdery mulch. If that is present, you have a borer working its way through your tree.

I've also heard several people in California complain about losing trees to gophers. I'm not sure what the damage looks like.

~james

The gophers eat the roots. Sometimes, after eating the roots free from the soil, they snatch the whole fig (if it's small enough) down the hole, into their run.

First growing season I was in southern California, a neighbor told me he planted a dozen tomato plants and went to get the hose. He said when he returned (in 10 minutes), he saw the last tomato plant going down the hole.

I routinely watched plants shaking and twitching--both wild and cultivated--and all of a sudden, disappear underground.

(Another true gopher story). Neighbor and I were having a giant pumpkin growing contest. As they grew we used to pick them up, periodically, and put them on a bathroom scale (when they were small enough), and later, when they got larger, we'd try and pick them up to gauge their weight.

They had gotten to about 90 pounds each--pretty similar in size (from same batch of giant pumpkin seeds)--and my neighbor picked his up one day, and it went right up in the air. Gopher(s) had tunneled up underneath the pumpkin, made a hole in it, and eaten all its insides out. It was just a giant shell. Must have had help from his whole family to eat all that pumpkin pulp.

I witnessed that with my own eyes. 90 pound pumpkin became a 10 pound "shell" in a very short period of time; a week, tops.