Quote Originally Posted by WashougalWonder
Yep, happens to me too, don't know why. Plants seem to do fine as they get older, but sure seemed scarey at the time....only happens to me with seeds, clones don't seem to do it. Though yours seem quite a bit worse, I usually get 3-4 sun leaves before I see lower leaves with this.
Same here, the four bottom-most leaves usually die on me like clockwork. Never really thought anything of it, I figured it had something to do with the plant switching its nutrients from the cotyledon to the nutes in the soil.

If it keeps spreading, check out your PH. That would be my best guess.