Sounds like they are not getting any water ,being that small plants have roots that are very short . growing your seedlings a couple more inches may increase their survival rate,
Did you plant in ground or container ?

Lori,

It does sound like too much rain/not enough sun. As dfickle asked, are they garden planted? It does sound like they drowned, which means the roots got no air. This type of extended wet weather prompted me to grow some (smaller - non super-large beefsteak plants) in grow-bags. Even a container with good non-clogged drainage holes will handle extended rains. The good thing it's still early- and Bonnie Plants has some heirlooms. -Randy

As I posted in a similar discussion just a bit further down the page, IME planting out in periods of extended rain, especially if is it also cooler weather, is an active invite to early fungus diseases.

But then you didn't really say what killed your plants. From your description above it sounds like it could be damp-off. Just a guess.

Dave

Thank you folks! I googled pictures of Damp Off. That's what killed them. I really should buy a gardening book instead of winging it LOL!

I'll just add, not sure how you started your seedlings, but the plastic Solo drinking cups provide enough room to get tomatoes well past the stage where they are vulnerable to damping off. Once your seedlings get thier first set of true leaves, they should be potted up to at least those size cups.

From that point they should be getting as much light as possible when the weather is good. You are also in NY, so for instance, if you started your seeds April 1st, by the second or third week of april, you should have them potted up and outside when the weather is nice. The sun in NY in april is not so intense, so you don't have to be real careful about hardening off. Just put them under a tree the first few times out.

Bottom water and keep them outside when the weather is warm enough to. Cool and wet? Move them back inside, keep them in a sunroom or in a south facing window. We had plenty of sun this spring to get your palnts to a very good size. Buying a book is fine, but I have learned all of my gardening knowledge from Gardenweb and the rest of the internet. You have to read a lot of sources, you will be able to discern what is good info, what is someone selling a product, and what is someone with little experience touting thier "system" after they are 4 weeks into thier first time growing anything in thier life ever.