HELP ME!

I have the most beautiful crop of Andrew Rahart's Jumbo Red tomatoes growing. Starting earlier this week I started finding huge soft spots on some (many!) of the fruit, which quickly turned to rot. These spots aren't appearing on the blossom end either....They're showing up on the top and side of the tomato. The spots are grey, then black, and completely mushy.

I found one this morning that was just starting to get a grey patch on it...about the size of a dime. When I took it inside and cut the spot out, the entire core of the tomato had already started to turn red, and the smell of rot was strong throughout.

I don't see any holes in the fruit like worms have gotten in. I killed couple of horn worms the other day, but can't find any more.

Anyone have a clue what this could be? I haven't been fertilizing these big old things much, can they rot if they're not getting enough nutrients? Someone please help, I'd hate to lose this gorgeous crop.

Thanks,

Matt