My first tomato question/problem

[mmarsee]

Hello All,
This is my first year growing from seeds and I hope someone can answer a question for me.
I check my plants everyday when I get home from work and tonight I found one of my speckled romans looks like it's wilting. I'm reading all different things but can't understand why it's only happening to this one. They are watered from the daily thunderstorms we've been having and full sun for over 6+ hours a day before. The soil they are in is all new and I made it from the guidelines of the square foot gardens Mel's mix. So I'm stumped!
Hopefully someone here can shed some light.
Thanks!