Thanks guys for your responses. I now have a new
plant just like it. The guy at Home Depot took my
plant out of its pot. The roots looked good and were
growing despite the dying leaves. Here are a couple of things that stand out from this experience.
1. I added almost all new dirt and very little of the original dirt. Maybe that was a problem.
2. I water heavily when I transplanted - until water started coming from the bottom of the pot.
At any rate I only watered this one a little before potting (and repotted using mostly its own soil) and I watered a little after potting. I am going to monitor the soil's wetness and probably water again in a few days if necessary and then again as needed probably once a week. Hopefully this one will be ok.