DC10 CREW DEPARTED ACFT WITH 1 ENG RUNNING.

Narrative

AFTER LNDG AT MSP ARPT ON RWY 12L; WE PROCEEDED TO TAXI TO OUR ASSIGNED GATE AT THE TERMINAL. THE SO WAS UNABLE TO START OUR APU. WE ARRIVED AT OUR GATE AND WERE INFORMED THAT NO EXTERNAL PWR SOURCE WAS AVAILABLE. WE ATTEMPTED UNSUCCESSFULLY 2 MORE TIMES TO START THE APU. AT THIS POINT; ONLY THE #2 ENG WAS RUNNING TO PROVIDE LIGHTING FOR THE PAX DEPLANING AND FOR THE CARGO HANDLERS IN THE CARGO COMPARTMENTS. APPROX 15-20 MINS AFTER BLOCKING INTO THE GATE THE PAX AND THE FLT ATTENDANTS HAD LEFT THE PLANE; LEAVING ONLY THE COCKPIT CREW. 3 COMPANY MECHS CAME ABOARD TO EVALUATE THE SIT. I DISCUSSED WITH THE MECH OUR LACK OF PWR FOR THE ACFT AND THAT OUR #2 ENG WAS STILL RUNNING TO PROVIDE ELECTRICAL PWR FOR THE LIGHTING IN THE CARGO COMPARTMENTS. WE AGREED TO LET THE ENG CONTINUE TO OPERATE AND THAT WE (THE PLT CREW) WOULD LEAVE THE ACFT IN HIS CTL. WE COMPLETED THE PARKING CHKLIST; EXCEPT FOR THE #2 START LEVER; THE ROTATING BEACON; AND THE PARKING BRAKE WAS STILL SET. THE SO COMPLETED HIS WORK IN THE LOGBOOK; HANDED IT TO THE MECH ON BOARD THE ACFT; AND AGAIN MADE SURE HE UNDERSTOOD THE #2 ENG WAS STILL RUNNING; WHICH HE ACKNOWLEDGED. WE; THE PLT CREW; THEN DEPARTED THE AIRPLANE LEAVING IT IN THE MECH'S CTL. DAYS LATER; A RPT WAS FILED BY A COMPANY MECH THAT HE ARRIVED AT OUR ACFT WITH NO FLC PRESENT AND THE #2 ENG STILL RUNNING. ALTHOUGH THE PROCS USED TO SECURE THIS ACFT AT THE GATE WERE NOT STANDARD; I FELT VERY CONFIDENT THAT THE ACFT WAS SECURE AND IN COMPETENT HANDS; AND THAT SAFETY WAS NOT COMPROMISED. HOWEVER; SOMEWHERE IN THIS CHAIN OF EVENTS A COM BREAKDOWN OCCURRED THAT CAUSED SOME INDIVIDUALS TO BELIEVE DIFFERENTLY.