BOMB SCARE CAUSES EMER EVAC OF ACFT AFTER DIVERTING TO TULSA.

Narrative

APPROX 15-20 MINS AFTER TKOF; #1 FLT ATTENDANT NOTIFIED COCKPIT CREW OF A SUSPICIOUS OBJECT IN THE SMALL COMPARTMENT ABOVE. THE FORWARD COAT CLOSET. INVESTIGATION BY COCKPIT CREW REVEALED A CYLINDER (APPROX 10' LONG X 4' DIAMETER) HVYLY WRAPPED IN PLASTIC AND DUCT TAPED TO THE SIDE AND FLOOR OF THE COMPARTMENT. WE STOPPED OUR CLB AT FL240. WE RECHKED THE MAINT LOGBOOK AND CONTACTED DISPATCH. WE DID NOT FIND ANY INFO ABOUT THE CYLINDER IN THE LOGBOOK AND DISPATCH CLAIMED THAT D/FW MAINT WAS UNAWARE OF ANY SUCH OBJECT ON BOARD OUR AIRPLANE. THE DECISION WAS MADE TO DIVERT TO TULSA. WE DECLARED AN EMER WITH MEMPHIS CTR AND ACCOMPLISHED THE 'BOMB ON BOARD PROCS' CHKLIST IN ACCORDANCE WITH THE OPERATING MANUAL. DSCNT; APCH; AND LNDG WERE UNEVENTFUL. THE 'EMER EVAC' CHKLIST WAS ACCOMPLISHED AND ALL PAX AND CREW EVACED ON THE ACFT (TAIL CONE) SLIDE ON TAXIWAY B JUST OFF THE RAMP. THE TULSA POLICE BOMB SQUAD DISCOVERED THE OBJECT WAS A CANISTER OF RAIN REPELLENT. A DETAILED SEARCH OF THE MAINT LOG (AFTER THE INCIDENT) DID INDEED REVEAL A CANISTER HAD BEEN LOADED IN AMARILLO ON THE FLT PRIOR TO US PICKING UP THIS ACFT IN D/FW. RECOMMEND: THIS EVENT WAS CAUSED BY IMPROPER LOADING; PACKING AND INCORRECT DOCUMENTATION OF A SUSPICIOUS ITEM; AND THE ITEM WAS INADVERTENTLY L ON BOARD THE ACFT. CORRECT LOADING AND DOCUMENTATION WOULD HAVE PREVENTED THIS INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THAT NO ONE WAS INJURED DURING THE EVAC AND; AS FAR AS HE KNOWS; NOTHING HAS BEEN DONE TO PREVENT THIS FROM HAPPENING AGAIN.