Baby Bird!! Help!?

I found a baby bird I think its a crow but anyway he was on the ground flapping around... now i made a makeshift nest for him and his parents lol came and fed him... tonight when i came home from work he was on the ground so i put him back up there 20 min later he fell again... so i put him in a box til morning when i can put him back in the tree... i dont know what to do... he might be hurt but i cant tell bc he cant fly anyways and just wobbles around... i dont want to take him to the vet they might kill him right?