John McClane goes to the roof and went to the helipad. He warns in on the radio to the police that terrorists have seize control of the Nakatomi Building. After yelling out to the dispatcher to send the police now, Karl, Franco and Fritz fired at McClane. He jumps onto the roof landing. Then he retreated away from the thugs to the door that leads to the ventilation fan. Karl send Fritz down below the roof and McClane goes through the fan using the Heckler & Koch MP5 gun to stop the fan. As he did so, Karl had Fritz go down below to block their intruder in and he and Franco tried to kill him there, but failed as he got away. Karl and Franco left the roof and joined Fritz to get their intruder.