Very sad. And failed SAR operation has to be demoralizing but I bet it's especially so when a young child is the subject.
Not necessarily. If the emergency is legitimate (and this isn't always the case), there are two broad types of operations with respect to outcomes:
1) ops where your group made a difference,
2) those where you did not (an individual sustains a 300 foot fall for example - just remove the remains)
We always analyzed each operation, big or small, in an attempt to answer the questions - What can we learn from this event? What procedures and protocols should we change in order to improve our operations? If your group responded promptly, deployed effectively, and operated efficiently, what more can you do, and what is there to demoralize you?
Operations with bad outcomes definitely do not lift your spirits, but those where you did make a difference, typically saving a life, provide a very noticeable exhilarating high. This definitely compensates for the flat spots.
Searches for young children are often among the most demanding....