It looks like flea beetle damage. Not really a problem as they usually get the lower leaves and the leaves higher up the plant are perfectly fine :).

Linda

Thanks, Linda, but this is happening at the top, as well.

Christy, I am working on a tomato research project. Your answer to the following question may be helpful. Do you make your own garden compost that includes the usual kitchen-type leftovers?

It would help posting pictures of the entire plants so the progress, or stages can be reviewed. The pictures you already posted of the leaves are obviously one symptom or sign and with the limited information you gave "All the leaves have curled up and turned brown" I suspect Thrip damage on the leaves, followed with tomato spotted wilt virus.

It does look like Flea Beetle damage but initial Thrip damage is also somewhat similar. If it's Flea beetle damage it can cause increased infections of Alternaria leaf blight (early blight) in tomatoes, its not the reason for early blight, just helps the blight to spread. If it's Thrips they transmit the TSWV, which your plants have no resistance to.

To catch a flea beetle hold flytrap paper, or white paper coated with vaseline over the plant giving the plant a little shake. The flea beetles will jump to the paper and get stuck and can be viewed.

To see a Thirp you need a magnifier because they're almost microscopic. If your phone has a magnifier app you can try that. It's one or the other IMO.

Bacterial spot is my first impression. Would lead to serious plant damage and isn't curable. Harvest your fruit, it's edible, then dispose of the plant.