What happen here?

A simple line divided the two detachments. One line dividing complete chaos.
                Thump, thump.
People move all around me, avoiding missiles flying at them from the other side of the line. I move to my right, and duck.
                Thump, thump.
Still alive ... barely.  My breath enters my lungs and rapidly retreats back out my throat. As soon as I'm out of danger I grab my weapon and hurl it at the opposing side. He never saw it coming.
                Thud.
He falls to the ground. A roar explodes from his compatriots. One less adversary, I think. Seconds later, three more missiles fly at me. One hits the ground in front of me. I duck as the second soars over my head.
                Thump, Thump.
But I can't avoid the third one. Before I can duck, the shot smacks into my head.
             Thud.
Another cry escapes the witness' lips. My neck cries out in pain as my part in the battle is over.

                WHAT HAPPENED HERE?
Winner of the 1000 gift pts is "The Lady Marine". The correct answer: Dodgeball.