Mother and chicks - threesome - for the last time

Sorry to inform that among the two chicks, one is no more. It is the smarter chick which used to grab most of the feed from the mother's mouth and grew up very quickly unlike the other. It used to be very active and agile. I had last seen it flexing its wings and could sense that it wants to try to fly. This, I am guessing must have been the cause of its death - it must have tried to fly away from a height of 8 floor building and met its last. After returning from work, when I found one of the chicks missing. Then I went down to see if I could see the fallen chick below on the ground somewhere, but did not find it. I waited for it to show up wishing that it has succeeded in flying about but no, it never returned. So, I am pretty sure it is no more. The other chick is now getting all the feed from its mother and so it too will start growing quickly.