Yes. Go to My Documents => LDW => Virtual Villagers 2 - The Lost Children, and look for a .txt file (I believe ldwlogs.txt, or something). That is your log file. Open it in notepad, and it will likely tell you what happened, but don't wait too long, and catch it before you open the game again, as it only holds history for so long.

My guess is that the children probably got sick with no doctor to heal them.