Has anyone ever missed a u'a not because it was going to be dirty but because of a death in the family and just plane busy and forgot if so what happens?

They violate you for missing it, and treat it like an assumed fail... most people that "miss one" do so because they know they are going to fail... So its assumed when it happens.

It was your responsibility to call them BEFORE the test was to happen. Also hope you kept your airline tickets and have a copy proof (ergo copy of death certificate) .... with positive proof they MIGHT go easy. Assuming you have not done anything else in the past to cast a doubt on you.