You could have transfered any disease that effects solanums in your compost by composting effected veggies of potatoes, peppers, even basils if it's verticullum (sorry, spelled wrong) wilt. It could be from a store.
Did you also add anything else, any other fertilizers - bone meal, blood meal... anything? Maybe it's nitrogen burn?

Maybe it is unrelated and wilt is just taking over your garden right now (it is hard for me to tell without seeing the whole garden and also some various leaves).

Treatment: this winter follow your solanums with brassicas. Brassicas are known for their ability to help "clean" the soil. Alternately, if you need to remove crops now if you feel they really are diseased you can plant buckwheat as a cover crop immediately. Follow that immediately with a cover crop of fava beans. Only cut the buckwheat right before it flowers - do not till it under. Let the favas grow and till or dig them under before they make peas. At this time cover the entire beds with black plastic tight as a drum. Leave the black plastic on during the rest of the winter and all of the spring and summer - you can not plant any of your solanums in this bed again for minimum one year anyway.

Lastly, did anyone smoke around your tomatoes? People forget that this can cause instant death around tomatoes. The characteristic of this effect is that many leaves, especially on the bottom (including the stem) withers quickly and hangs like it is hanging on a thin thread. Overnight!

Personally, I have a feeling it could simply be that the heat and rain is just causing disease to spread. I am getting some on my Juliette's which are very resistant. The solution is to carefully cut each disease leaf off. Keep with you a small container of rubbing alcohol and (I wear neoprene gloves for this job) - after each plant and on a very infected plant, after each cut - you clean the blade and after each plant clean your palms with rubbing alcohol (or chlorox wipes if you are not organic, or it is more convenient). Do not let the infected foliage touch other non-infected foliage during this process as best you can (for interior leaves I reach in and close my fist around them and snatch it out, carefully, then wipe palms). Dispose of in the trash. Do not crush any dried leaves. The dry leaf will powder and send spores thru the air.

That's my best advice. I've saved all but two tomato plants from a fairly infected garden this way. Every one is now low in leaf but full of healthy fruits and the rest of the remaining foliage and the stems are disease free!!!

You are so smart! You should have your own gardening TV show! Look out Walter Reeves! Thanks for the advice! I need to print out your response and use it as a guide.

And, did I mention, peppers and eggplants are totally healthy!

What about the scorch-looking thing that is happening to other plants? Just in areas where I've amended with compost.....

If the peppers and eggplants are healthy then you have tomatoes with blight and NOT verticulum wilt. Go ahead and do the cut and dispose leaf method and see if you can get your tomatoes to come through.
Plant cabbage in the winter there (or broccoli, kale, collard)
Maybe try some arrugla and/or cilantro there (or lettuces) in the spring
in summer plant beans

and in two years you can try tomatoes again.

I'm having the same issue. The cause is apparently the early spring wet and hot weather.

Two years before I can try tomatoes -- whatever will the poor squirrels do? The little poops might starve! Hee hee. They actually look ticked off when they go in the bed and can't find any good tomatoes.

Thanks again for the help!

No, just in that area. Put your tomatoes in another area, and you'll be fine. Remember the problem is purely in the soil and not in the air.

I have been planting tomatoes here and there - but I'm going to start next year by using only dedicated spots for certain crops. This will help me better keep track of crop rotation.

GGG