This spring I've watched four sets of hummingbird babies on two different sites. The first set fledged without a problem. The mama disappeared for the second pair of babies. The third pair either died from the heat and were eaten by ants or were killed and eaten by ants. It's not an easy world for hummingbird babies.
This pair is about to fledge. You can see them here.
Update: they successfully fledged! Here is the very used empty nest. I wish you luck little ones.