I'll reserve speculating until more info is released by LE/ME. It doesn't take but a few seconds for a child to disappear. We're not all super-human parents and grandparents. We get comfy in our surroundings and routines and with that, we sometimes let our guards down while "real life" happens. Moreover, if homicide investigators are out there, odds are there are reasons to believe someone took and harmed Tootie. That someone could have very well planned this ahead of time by simply being familiar with the family and their routine.