"I don't consider myself a hero. I consider myself a hard worker."

That's Jose Melendez-Perez's take on his role as an immigration inspector in Florida. He stopped a man from entering the U.S. in August 2001 because of the man's body language, because he didn't have a return ticket, because his stated plans as a tourist didn't make a lot of sense.

Four planes were hijacked on September 11, 2001, with five terrorists in three of the planes. The one that had four hijackers was Flight 93. If Jose Melendez-Perez hadn't been such a vigilant worker, Flight 93 quite possibly would have had five hijackers, as well.