Goodbye, Pookie

I found him on my way home from church. He was struggling across the street and not able to jump the steep curb onto the sidewalk. I was on my bike and nearly ran him over. A small, feathered bird that couldn't yet fly. I couldn't just leave him out for a car or a cat or something to take him away, so I called B, who came with a bowl to transport him back to the house with. I went to Petco. I got a cage, food, worms, whatever I thought I needed. I put him in and he seemed fine. I gave him water from a dropper, I gave him worms from a tweezer. He seemed fine. My cat sure liked him, liked him a little too much, but I made sure that Pookie was in a high place away from claws and teeth. Pookie made it through the night. He woke up chirping and chirping and looked like he pecked at some of the food in his cage. I took him out on the rooftop and let him out of the cage. He could fly a few feet but couldn't get completely airborne. "Just a few more days," I told myself, thinking that he would just need a little time to get the strength up to make his way into the world. He seemed fine.
But I came back from playing tennis in the afternoon and found Pookie on his side in his cage. He wasn't fine. He was dead! I had tried my best to take care of him but failed miserably and wondered what I could have done differently. I guess I'll never know.