I don't think that's Blossom End Rot because the lesions aren't located in the exact center but off to the side.

I am not immediately seeing the problem using the TAMU Tomato Problem Solver

Were the fruit touching the soil? When you water the plant, do you water the leaves and fruit, or just the soil? Watering the entire plant can lead to many diseases, fungus, etc.

This probably isn't the issue, but make sure that 18" clay pot has a capacity of 5+ gallons. If this was a 32 quart bag of Potting Mix, then you should have used over half of it for each 18" pot.

Someone with knowledge of diseases will have to chip in here.

Do you have fruit or ear worms in LA, for I know some do?

It looks like rotten areas secondary to worm invasion.

It isn't BER.

Are there any leaf symptoms?

Carolyn

Thanks for your replies.

The leaves are showing no symptoms and neither of the tomatoes were on the soil. They were, however, right next to each other.
When watering, I water only the soil. I'm careful to not get the leaves wet.

I'm not sure about the fruit or ear worms. The skin of the fruit was not broken, however.

I'm not sure about the fruit or ear worms. The skin of the fruit was not broken, however.

With pinworms/earworms/fruitworms you wouldn't necessarily even see a puncture mark or hole.

NO leaf lesions and no wilting suggest that the lesions were caused by critters, at least it does to me. And doing some Googling might be helpful in that regard.

In addition to Googling if I were you I'd also check out whether or not you have such critters where you are and a call to your local extension service might be in order.

Carolyn