Contact a licensed wildlife rehabilitator. You should be able to find one here: http://www.tc.umn.edu/~devo0028/contact.htm
Licensed wildlife rehabilitators have the specialized training to care for sick, injured and orphaned wild animals, and they have the required state and federal licenses that allow them to keep the wild animals until they are healthy enough to be released.
Do not take the animal to a vet - vets are for pets, and most vets do not have the expertise to care for wild animals; nor do most vets have the proper licenses that would allow them to keep a recuperating wild animal.
Do not attempt to care for this bird yourself, either. First, the injuries are serious enough to need a medical professional. Second, in the US, all native migratory birds are protected under federal law (Migratory Bird Treaty Act), and it is illegal to keep any protected bird unless you have the required permits. Penalties for violating this law include up to $500 and/or up to 6 months in jail for each offense. http://ipl.unm.edu/cwl/fedbook/mbta.html
Many other countries have similar laws pursuant to the Migratory Bird Treaty Act, which is an international treaty, protecting their native species.
When transporting the bird to the rehabber, keep it in a warm, dark box lined with paper towel (not a cloth towel, as the bird can get its nails caught in the material). Until you can get it there, do not attempt to feed it. No injured animal should be fed before being examined by a professional, as it may have internal injuries. Also, do not attempt to give it any water. It could aspirate and die.
Get it to a rehabber as quickly as possible - today, or first thing in the morning - so it has a chance of surviving.
Best of luck with it, and you and the little feathered one have my prayers.