The mourning practices are not put into play during Chol HaMoed, though if the person who died is a sage or a righteous person, the Chol HaMoed exemption shifts to acknowledge the more communal mourning. Note also the attempt to explain the WHY of one's children's deaths - which the Gemara explores in ways that fly in the face of our understanding (or lack thereof) of why such things happen. Also, the eulogies of the sages - in their poignancy and strength, and perhaps surprising detail, and even supernatural effect.