I just heard on the car radio (I'm in NY this week) that apparently a flight from Columbia landed in Miami. After the flight landed, a man on the flight "brandished" a bag that he said contained a bomb and went running towards the cockpit--the air marshal attempted to stop him. Somehow (not made clear by the broadcaster) once the man was outside the plane, he reached into the bag at which point the marshal had not choice but to shoot him. The suspect is dead. No word yet on weather or not there actually was a bomb in the bag.
A couple of my friends were trainers for an Air Marshal program a couple of years ago. It appears that they did their job well.