Where has Harold Camping gone wrong?

According to Harold Camping the Secret Rapture was supposed to take place on Saturday 21st May at 6 pm across the world.

Camping had been announcing for sometime that Jesus Christ would then return to this world, that the righteous would be raptured up to heaven. He estimated that around 200 million people would be raptured or about 3% of the world's population. There would subsequently follow five months of fire, brimstone and plagues, with millions of people dying each day. This would culminate five months later, on the 21st Oct 2011, with the end of the world.

However, 21st May has come and gone and there has been no evident rapture and no subsequent plagues etc falling upon the world.

This non event begs the question where has Camping gone wrong?

1. Harold Camping displays the marks of a false teacher
2. Certain events are to precede the coming again of Jesus Christ
3. There is no 'Secret Rapture' taught in the Bible.