Thank you for your question to Extension. Without a picture of your tomato wilt for me to see, I can help by showing you the most common tomato wilt disease right now, which is called early blight. This blight causes round spots on the stems and wilting of the lower leaves, progressing to wilt moving upwards. It will cause the fruit to become spotted dark, with fruit falling to the ground. With our extreme rain earlier in the spring, many tomato plants are suffering from blight. Here is information from Extension: 

Early blight in tomato and potato | UMN Extension

If you don't think this is what your tomato plants have, send pictures and we will look further into your problem.