TC feedback front DT "A" side cab door open when departing. TC used the strap to secure the affectedcab door and Isolated in closed position at MSP Siding. ~~~~~ #3558-A/S cab door found latch mechanism mounting screws loose and missing.Resecure screws and tested ok. Check B side cab door and #3557 A & B cab doors security ok. Done by Tay H.K. 05/09/21