DC >> Supergirl and the Legion of Super Heroes ( Volume 4)
by DC A captain and an officer of the Science Police discusses the organization called The Legion of Super-Heroes as a macrobot experiment breaks loose in Metropolis. The captain demands that the Science Police will take care of the robot, but is then informed that the Legion already did that, and when asked "how", the officer simply responds "...they hit it, sir."
On the scene, a couple of Legionnaires are shown to have taken down macrobot. Colossal Boy detaches its head and gives it to Ultra Boy . Science Police troops appear and demands that Ultra Boy drops the head to the ground. Too late, they realize what a bad demand it was since Ultra Boy dropped the head just above them (even though Light Lass caught it with her anti-gravity field). They escaped the scene (still having the macrobot head) moments later.
Thats how the comic begins but in issue 16 Supergirl joins the Legion and nothing is ever the same again.