What should i do if baby robins fall out of their nest in my yard?

So there was a nest of four baby robins in my front yard and today we saw a hawk circling around our yard. We thought the hawk had gotten the baby robins so we went to make sure the baby's were still there. When we checked on the birds they freaked out aand all four of them jumped out of the nest. I don't if i should try to care for them so they don't die or just leave them be. what should i do ??? I want the babies to make it!!