Here is the story of one man who did make a difference:
"The passenger was Elton Simpson, one of two radicalized American citizens who had come to attack the crowd at the Culwell Center, shortly before 1900 on May 3, 2015, in the name of the Islamic State in Iraq and Syria (ISIS).
Wearing soft body armor and load-bearing equipment (LBE), and carrying a pistol and an ominous backpack, Simpson exited the car with a smile and began firing the rifle, which fed from a 100 round drum magazine.
Witnesses said the rifle was fired so quickly it sounded as if Stevens and nearby Garland Independent School District Security Officer Bruce Joiner were taking automatic fire.
The smile on Simpson’s face gave Joiner the impression it was all a joke, but when Stevens saw the rifle barrel poke out of the car, he immediately recognized the threat for what it was, and also recognized that his tactical position was poor.
Stevens was standing in the open, with no hope of reaching any kind of cover, when Simpson tracked the rifle toward him and the unarmed security officer to his left rear. Stevens instantly recognized that the only way he was going to prevail in the coming fight was to aggressively engage Simpson and the driver, who was now exiting the vehicle on the far side with a drum-fed, AK-pattern rifle of his own."