In very hot, humid weather, Fatsias can get a fungal collar rot, especially if they are watered frequently, and/or in a slow-draining clay soil. It's hard to stop, once it starts, but improving the drainage, and mulching, so it needs less frequent watering (and the roots stay cooler) will help prevent it in future plantings.

Thank you so much. I lost one plant and I moved the other back to a pot and have been spraying it with antiseptic mouthwash mix, according to a Jerry Baker Book recipe, hoping I can save the other one.
Thanks again,
Twazy

Here in Phoenix, we have to move them indoors every summer, along with our Jade Plants and Sheffleras--for the same reasons.