Basil up-potted and mixed with vermiculite -- here are the tips I received

 "I’d say either went too long without water or you put cold water on the leaves when watering."

"I had this problem with few leaves. I was watering too much I guess. So I pinched those leaves and dried the soil completely before watering more."

"They need to be re-potted out of the seedling tray and into pots."

"If leaves are wilted slightly or damaged, even t8s will burn them to a crisp. Lack of water or too much could be the cause but as Lori mentioned those cells look really small. Definitely get those little guys potted up"