King and the guard

A night shift guard, while on patrol at night, dreams that the king will die in a plane crash. He tells the king so in the morning, but the king tells him not to worry, and flies anyway. When he returns from his trip, he fires the night shift guard. Why does the king fire the night shift guard?

The night shift guard had a dream. He therefore he was sleeping on the job.
Reveal Answer
From The Logic Riddles Section!