Q.What\’s Causing The Leaves To Die?
I don’t see any pests on the plant. I water when the top 2 inches is dry. Our daily temperatures are in the 90’s. The plant gets partial shade in afternoons

Certified GKH Gardening Expert
The first thing to do will be to test soil pH and nutrient content.
If tests confirm that everything is in check, then I could suspect that the container may not have enough drainage holes.
If the container lacks drainage holes, or doesn't have enough to let ALL extra water out, completely, then this could likely be the issue.
A container without drainage will allow water to pool up in the bottom of the container and, though the top may be dry, the bottom of the container can be too saturated. This can cause disease.
Amend according to the soil test results, or treat with a fungicide, should the results come back normal for pH and nutrient content.
Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/edible/vegetables/tomato/growing-tomatoes-guide.htm