MD80 IS DAMAGED AT GATE WHEN MOVEMENT OCCURS AFTER BRAKES RELEASED PER PARKING CHECKLIST.

Narrative

WE BLOCKED IN THE GATE AT XA10Z. THE APU WAS OFF AND WE WERE WAITING FOR GND PWR. WE SHUT DOWN ONE OF THE ENGS. AT THAT POINT THE GND CREW INDICATED TO THE CAPT THAT THE CHOCKS WERE IN PLACE. THE CAPT TOLD ME THAT HE WOULD NOT RELEASE THE BRAKES UNTIL WE HAD GND PWR AND THE OTHER ENG WAS SHUT DOWN. WE THEN RECEIVED GND PWR AND COMPLETED THE SHUTDOWN WHICH INCLUDED RELEASING THE PARKING BRAKES. AFTER THE CHKLIST WAS COMPLETE; THE CAPT GOT UP TO OBSERVE THE PAX DEPLANE AND I COMPLETED PAPERWORK. SINCE THEY WERE STILL DEPLANING; I STARTED THE PAPERWORK FOR THE OUTBOUND LEG. AT THIS POINT I WAS SITTING WITH MY FEET IN THE CTR AISLE OF THE COCKPIT. I THEN HEARD YELLING AND LOOKED UP TO SEE WHAT WAS HAPPENING. I NOTICED THE JETWAY MOVING AND WAS A LITTLE CONFUSED AT THAT POINT. ONCE I LOOKED OUT THE FRONT WINDOW; I REALIZED THE ACFT WAS ROLLING BACKWARDS AND IT WAS NOT THE JETWAY MOVING. AT THAT POINT I REPOSITIONED MYSELF TO APPLY THE BRAKES. THE CAPT RAN IN THE COCKPIT JUST AS I APPLIED THE BRAKES. HE SET THE PARKING BRAKE AND WE PROCEEDED TO MAKE SURE THE FLT ATTENDANTS AND PAX WERE OK. AT THAT POINT WE NOTICED THE DAMAGE TO THE L1 DOOR. MAINT INFORMED US THAT THE WINGTIP HIT A FUEL TRUCK. GND CREW TRAINING NEEDS TO EMPHASIZE THE IMPORTANCE OF CORRECTLY INSTALLING CHOCKS AND NOT GIVING THE SIGNAL THAT THEY ARE INSTALLED UNTIL THEY ARE SECURELY IN PLACE.