DEP TKOF DELAY CREATED BY SUSPECTED BOMB THREAT.

Narrative

AFTER CREW BOARDING; CABIN SVC FOUND A PAPER SACK UNDER A SEAT IN ROW 9 STATING THAT 'DO NOT OPEN BELOW 10000 FT AND IN SEAT OR ANYTHING COULD HAPPEN.' NO PAXS WERE ABOUT THE ACFT AT THE TIME; AND THE ACFT HAD PREVIOUSLY ARRIVED FROM SJU AND STX. I INTERPRETED THIS AS A POSSIBLE BOMB THREAT AND HAD THE CREW AND CLEANERS LEAVE THE ACFT AS A PRECAUTION. WE CALLED OUR RAMP CTL AND REQUESTED THEM TO SEND SECURITY AND NOTIFY THE COMPANY OF OUR SITUATION. THE LEAD GATE AGENT CAME DOWN THE JET BRIDGE AND I INFORMED HER OF THE SITUATION AND TO DELAY BOARDING. THE NEXT THING I KNEW; SHE WAS WALKING OUT THE ACFT DOOR CARRYING THE SUSPECT SACK. WHEN I ASKED HER 'WHAT THE HELL SHE WAS DOING;' SHE SAID THAT SHE PICKED UP THE PACKAGE TO READ IT; AND FIGURED SHE WOULD CARRY IT OFF SINCE SHE HAD ALREADY MOVED IT. FORTUNATELY; THE PACKAGE WAS FALSE; BUT I STILL HAD IT PLACED ON THE RAMP UNTIL SECURITY COULD CHK IT OUT. THE AGENT ASKED ONE OF THE FLT ATTENDANTS IF THE FLT MIGHT STILL DEPART ON SCHEDULE. THE ACFT WAS SEARCHED AND ALL THROUGH PAXS HAD TO CLAIM AND INSPECT THEIR LUGGAGE FOR ANY UNKNOWN OBJECTS. NONE WERE FOUND. THE FLT DEPARTED APPROX 1:30 HR LATER USING A SUBSTITUTED ACFT. I AM CONCERNED ABOUT AGENTS DISREGARD FOR SAFETY IN ORDER TO BE 'ON TIME.' THIS WAS NOT THE FIRST TIME OUR AIRLINE HAD THIS EXACT SAME PROBLEM. ALL AGENTS NEED SOME SORT OF SECURITY TRAINING AND EMPHASIS AWAY FROM THE INDUSTRY'S ON TIME PRESSURE.