The yellowing leaves don't look particularly diseased, but perhaps they have a nutrient deficiency due to being so crowded. At this point you may need to break the pot and pot up each one of the original bulbs in fresh soil. If you do repot, you probably will have to reduce the length of the remaining leaves, so they don't wilt too much. The baby bulb with the one root doesn't worry me too much. Sometimes they do take a long time to put out roots. Since it is only in this one clay pot, it is certainly worth trying to save the bulbs. If this is something that is spreading, then you might have a disease issue. You can use a systemic rose/flower anti- fungal treatment if you are worried about disease, but I don't think you are at the point quite yet. As Christie said, it could definitely have something to do with heat stress.
