The curious case of the dead bird

I'd just finished a morning session at a big international bank in Otemachi, and was walking toward Tokyo station to catch the Yamamoto line to my office in Tamachi. The sun was out but it cast little warmth to the crisp winter air that stung my cheeks. I dug my hands deep into the pocket confines of my jacket, and moved swiftly through the gathering lunch time throng of rumble tummy salarymen.
Up ahead, along the pavement, I discerned a small black shape. At first I took it to be a rat but as I drew nearer I realized it was a bird. Not being an ornithologist, I couldn't identify what kind of bird it was, but I could definitely, without a doubt, tell it was dead.
It lay on its side, coloured black but with some gold flecked around its head. If I had chosen to pick it up, it would have sat comfortably in my palms, but I didn't, a little afraid of touching death. There was no obvious damage to the body and I could see no blood, either on its body or in the immediate area surrounding it. I looked up to see if there were any other birds flying in the vicinity, but the sky was empty of any living creature. Only the glass reflections of the many glimmering shards of finger pointing glass skyscrapers glinted up there.
The bird looked healthy, but it was very dead. Maybe it had flown into one of the impossibly tall buildings crowding the lower sky way or had had some sort of avian heart attack. Or maybe it had eaten something that really didn't agree with its constitution, sending it crashing to earth in a writhing agony of regret.
I pondered this as I continued walking, glancing back only once to see two young office ladies peering down at the curious case of the dead bird, and smiling to myself unconsciously as they both recoiled in exaggerated disgust, emitting high pitched screams tinged with nervous laughter.