Really bad infestations can be treated systemically by a certified arborist. Most likely your tomato plants were infected with verticillium wilt, a very common fungus that attacks the tomato family. Scrupulous fall cleanup of infected plants is very important as the spores will overwinter in fallen leaves. Rotation of crops within the garden and use of verticillium-resistant hybrids will help eliminate recurrence. Something is making tiny holes in my cabbage and brussels sprout plants.
Flea beetles are the most likely culprits.
Most of the damage is done in early spring when the plants are small. Floating row cover material is useful as a barrier until the plants grow large enough to withstand the chewing. A spray of pyrethrum is also helpful. Parts of my healthy-looking squash plants suddenly wilted and died. A sudden wilting of squash-type vines is often caused by the larvae of the squash vine borer moth which bores into fleshy squash stems effectively killing that part of the vine.