100% of all end-of-the-world predictions have been wrong. It's like playing a lottery you have no possibility of winning. Has Mr. Camping ever read Matthew 24? Perhaps he is really trying to predict his own passing?
When I was in junior high one of my friends told me the world was going to end on such-and-such a day. She knew because there had been a speaker at her church and the speaker showed them all the signs from the Bible that had "come true". My friend told me to read the Book of Revelation and that it would scare me to death. I did read it, or tried to, but found it too confusing and gave up. Decided to pray instead. And wouldn't you know, here we are +/-35 years later, still waiting for the world's demise.
Whatever will be, will be. The future's not ours to see. Que sera, sera. What will be, will be.
UPDATE: There was a 4.0 magnitude earthquake near the Family Radio headquarters!!! I cannot imagine the reaction inside that building. ROFL
I tried to find something about end times predictions in the late 70s to pinpoint what my friend was talking about and I found this list of predicted dates of the end of the world on Wikipedia (Martin Luther made the list!).