I am pulling my hair out on this one. I have always been able to find out what is affecting my tomatoes, but this one has me boggled. We always have problems with southern blight, but I seemed to have gotten that one under control. Then we walk out and two of my plants are wilted and died in a matter of a couple of days. Today a third one was wilted when we woke up. They look fine one day and wilted the next. This time though we have seen what is going on, but I can't seem to figure out what it is and how to treat it. I have tried fungicide, but it doesn't seem to be stopping it. Please help if you can.

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