I am a novice Gardner and I have having an unusual problem with my tomato plant this year. It appears that they are damping off at the base of the stem. Here are the facts:

I have raised beds in my yard in which I plant my garden. I purchased my tomato plants from a local nursery this year. They were smaller than average when I planted them a couple of weeks ago. Since then, I have had 8 or 9 of the plants just fall over and die. They look like something attacked them right at the base of the stem. I had one die and I replanted it. (Not that unusual to have one that doesn't survive the transplant - for me anyway.) Then I had three more die in the same manner which I thought was unusual however I pulled them out and replanted with some extra's that I had. Now I have had at least 4 more die in the same manner. They are all in the same raised bed and they are all on the same end of the bed. As it stands now I still have about 5 or 6 plants growing in that bed. None of the tomatoes I have planted in other beds have been affected as of yet. It has been an very wet and sometime cool spring. I guess I would like to know if this is a disease in the plant, something in the soil or possibly a pest of some kind. And then if someone has advice on how to deal with this I would really appreciate it. I have posted some pictures (hopefully)