I agree with oldjarhead, when plants are this young less is more both for nutrients and watering. The soil looks a little compact (no perlite or other additive for drainage) so it can stay wet for a long time. Good soil also has enough nutrients in it for at least a couple of weeks so no need to overwhelm the young plants with all that nitrogen. Just give it good light, humidity and temperature, only water when the top half inch of soil has dried. Wait until the plants recover before reintroducing nutrients and then only at half strength or less for a while. They should recover and best of luck to you. Let us know how it all turns out.