Becca, you are experiencing the heartbreak of vine crops. I wish I knew what to say to help your problem as I have experienced the same thing...perhaps a virus or the like??

Cantaloupes and watermelons can do that from wilt diseases, but squash?

I don't have any pictures, I've been pulling the plants and putting them in the trash when they die. The one I pulled this morning had a great root system on it. I did see squash bugs and eggs....I didn't think squash bugs would kill a plant, I thought they laid their eggs on them (which I would assume they would need a live plant for this) and that the squash bugs would kill the blossoms not the plant. I'll have to look into the bacterial wilt problem from them as I have never heard of that before, still pretty new to gardening, on my4th or 5th year. Moved 2 years ago and never had the problem before!

I'd indict the squash bugs before bacterial wilt. Unless controlled, the young nymphs suck the plants dry. Squashes are much less susceptible to b wilt than cucs and melons.

here is a link that may help. the best guess is fusurrium wilt. try cutting into the vine to see if there is streaking. without a picture hard to tell.

Here is a link that might be useful: maybe this will help

Thanks for the link! I'll try and get pictures on the next plant that kills over! After reviewing the link and reading the descriptions of the different cucurbit leaf disorders, the Phytophthora Root Rot sounds pretty spot on! There is no discoloration in leaves what so ever and as the description statated "Symptoms may be hidden until "apparently" healthy plants collapse very quickly.....Plants often wilt and die without changing color". This describes what is happening exactly! We are using drip irrigation, which we are new to this year and our soil is very heavy clay, although we have tried to amend it the best we can. We have been watering about every other day due to the extreme heat, the drip irrigation is designed to put out about a gallon per our per plant, so perhaps we are watering to often!

I didn't know that squash bugs could do that to a large plant! I try to stay on top of them, but they are just horrible to keep up with!

Well I found I can take plants and bugs to my local Agricultural Extension Office after contacting them. So I was told any time M-F 9 to 5, I promptly went there since I had one of the plants with me that just died this morning only to find out they only do plant diagnostics M-W....bummer! Guess I'll have to wait for the next one and hope it is on a day they will look at it.

I started thinking some more though, I wouldn't think it would be the root rot from the new drip irrigation system that I am not that experienced with since I had this problem last year but only with the Zucchini and summer squash. I will taper back a tad on the water schedule...the 100+ degrees is gone for now, but I really wasn't watering every other day like I thought I was, I would go at least 2 days in between waterings sometimes.

If I find out anything from taking a plant in to be looked at I'll be sure to let everyone know how it goes...everyone is such a great help on here!

My Pumpkin plant is suddenly dying too! I also have a drip irrigation system, so I just don't think it could be root rot. I also have squash bugs, but I keep their population under control. I dug around in the stem, carefully, and couldn't find any sort of root worm. I did find one wire worm, I've had problems with those in the past in my potatoes.
The plant suddenly wilted yesterday, I gave it an extra round of watering, and it perked up to normal last night. It got watered again this morning, and now in the heat of the day it's looking worse and worse. Could it be some kind of wilt?

Hi jbaldwin! I was told my issue was the squash bugs. It is also normal for squash plants to wilt during the heat of the day and perk back up when the evening cools off, could this be what is happening?

I know this is years later, but squash bugs often introduce bacteria. I have had one butternut squash out of 3 in a hill and a large healthy squash plant perish overnight. All had controlled populations of squash bugs (is there such a thing?). I am pretty sure this is what did it.