A man is on fire. This is spotted by a second man, Todd.
The man on fire is running. He is running very quickly, away from what Todd can see to be a large explosion. Todd assumes that the man does not realise he is on fire.
Todd has a hero inside him. This hero leaps forth. He is also called Todd. (They're the same person.)
Racing to intersect the man on fire's path Todd knows that he must force the man to drop and roll. The less he is on fire the better off he is.
Todd sprints and has enough energy to shout at the man on fire to drop. He does not comply. Todd thinks he did not hear.
The man on fire did hear though. He cannot drop and roll. He's running through an inch deep pool of kerosene. He is running to a place where the ground is not covered in fuel. That is where he would prefer to drop and roll.
Todd ignores the splash of what he assumes to be water and selflessly tackles the man on fire to the ground.
There were no survivors.