Digging them up now would do absolutely nothing, necropsy is done on fresh bodies only, or fresh frozen.
Hair falling out around the ears and stop eating, sounds like soremouth. Takes about 2 days for a kid who is eating or drinking nothing to die, so that would be my diagnosis
Give them an information sheet on what to feed, how much to feed, and simple things you would never think about, like putting out water (in tiny kids in a bucket that if they jumped into would tip over). A guy came out to purchase two milkers and two bucklings just last week. He called that same night worried that the goats may swim across the pond to get out of his property which wasn't fenced on the other side. The goats will not swim across your pond, the goats won't get near the pond

In fact if you expect them to drink out of the pond you will have to teach them that the pond is for water....might want to put some buckets of water up at the barn.
Most deaths of kids is simple missmanagement. Buying bottle babies weaned to young, the kids starve to death slowly. No water offered when they are getting very little milk. No calories offered to kids when it's to cold out, and they are expected to eat grass to live off of when weaned to early. Vicki