Could Harold Camping be sued for promissory estoppel?

I thought this was an interesting concept. If someone lived the last few weeks as if it were really their last, neglected bills, ran up debt, etc. based on the promises or as he put it "guarantee" that the world would end on the 21st. Obviously, it didn't, so in this hypothetical scenario where someone relied on the promise of another, could he be held liable for promissory estoppel?