Robins will run about unable to fully fly with the parents feeding them on the ground for quite awhile. A good portion do die. When you talk to rescuers most have the opinion of that's life and it causes them an even slower more painful death to try to keep them alive or that it's worse to end up living in captivity. Also quite illegal to keep one in captivity without a license and most of the people that have a license don't have room for more animals. The death rate of birds in human hands is about the same as the death rate of birds left out in the wild.
If you want to try to keep it alive you need something better than worms. Most I've talked to have said not to feed worms at all for various reasons. Robins eat a wide variety of foods and dog food is actually pretty close as far as the mixture of grains and meats. Other suggested meats are boiled chicken, boiled eggs, kidney, liver, or meat baby food. Grains can include baby cereal, wheat germ, or oatmeal. Eventually fruits, vegetables, and insects (mealworms from a petstore are safer than wild caught insects) can be introduced to the diet. I've seen a few recipes using the parrot hand feeding formulas in petstores but I can't find them.