When I was about 10-11 and I was walking to school (we did that back then) I saw a bigger kid repeatedly throwing a small object on the sidewalk. As I got closer, I saw that it was a baby sparrow and I chased that kid away from it. That small sparrow had a broken wing and a broken leg, so I skipped school that day, splinted the leg with match sticks and taped the wing in the folded position. My mom was a very caring lady and we took that sparrow to a vet and he told us that we had done a good job and the bird would heal normally.
We fed that bird rolled up bread and milk until it grew its tail to full length and that sparrow was great companion for years - she would fly around at night, fly in my open window early in the morning and wake me for my paper route - then ride on the handlebars of my bike while I delivered the newspapers!