What was found
AFTER TAKEOFF, THE CABIN WOULD NOT PRESSURIZE. APPROXIMATELY SIX MINUTES AFTER TAKEOFF, AFT CARGO DOOR LIGHT ILLUMINATED FOR APPROXIMATELY TWO MINUTES. FLIGHT RETURNED TO DTW AND LANDED WITHOUT INCIDENT. FOUND DEBRIS IN AFT CARGO DOOR JAMB. REMOVED DEBRIS AND INSPECTED DOOR AREA, PRESSURIZED AIRCRAFT AND ALL CHECKED GOOD.