For a bunch to do that overnight my first thoughts were mechanical damage, such as a vole or mole digging underneath, or a herbicide. I killed a couple of my tomato plants a few years back by using too fresh chicken manure and bedding too near to them. I tried putting it a distance away as mulch but didn't work, so they died. So did you over-fertilize?
Maybe a disease? Especially with all the rain you are getting, do you have some type of fungal wilt or something like that. Or are they drowning because they are water-logged? I think it may somehow be related to all the rain you are getting. I think you are getting a bunch of rain out of these systems.