TC asked because it was most likely going to happen soon. It is a bad thing but completely to be expected in the situation.
I hope you managed to get some chicken vitamins. I am also going to ask if you are sure you picked up chick crumbs from the store and not just chicken feed. The reason I ask is because you say you had to grind it down which indicates it might not be chick crumbs which is what they should be eating.
Weak chicks usually just need time to rest in warmth to finish developing a bit longer than the rest and vitamins helps this along. Sugar water provides a bit of energy but nothing substantial, it's good to use if a chick isn't eating but if a chick is eating sugar water will just be an added placebo. Vitamins on the other hand will give him a real boost to gain strength.
Think if you wake up in the morning would you rather have a) a scrambled egg or b) a bag of sugar. The bag of sugar will make you super alert, you will start bouncing up and down and it will seem like you have got the strength of superman, the egg will be more slow release carbs and will slowly give you energy for a brisk hike across the countryside, some people say two large eggs is enough to sustain a person for a day.
Which is the better choice? Hard to say, I would love to be as strong as superman but after the sugar rush wears off I always just end up sleepy. I've tried eating even more sugar but I still couldn't fly.
Anyway back on topic, once he has more strength he will eat and drink more and the more he eats and drinks the stronger he will get, he will always be a week behind the others in growth but that is why you give him extra vitamins to help him catch up. Every day needs to be a slow improvement but it won't happen overnight.