On February 20, 1996, approximately 0715 Pacific standard time (PST), a Boeing 767-332, N125DL, experienced an APU exhaust fire at Portland International Airport, Portland, Oregon. None of the flight or cabin crew were injured, but three of the 135 passengers received minor injuries, and one sustained a serious injury. The scheduled Part 121 domestic passenger flight had come to a stop while taxiing for takeoff in VFR conditions. The intended destination was Los Angeles International Airport. According to Delta Air Lines, the crew of another aircraft reported flames and smoke coming from the APU exhaust of the 767 while it was taxiing for takeoff. The 767 crew shut the APU down, and began coordination with their dispatch for returning to the gate. They were then directed by Portland Tower to hold position and shut down the aircraft's engines. Soon thereafter, Portland Tower advised the crew that the Fire Marshall had said to evacuate the aircraft because there was still smoke coming out of the exhaust. The flight crew then activated the APU fire bottle and initiated the evacuation, which was carried out via the evacuation slides at the door exits. According to the cabin crew, although some passengers were hesitant about jumping onto the slides, the evacuation proceeded in a calm and orderly manner. One passenger sustained an ankle fracture during the evacuation process. After the accident, the aircraft was inspected for smoke and/or fire damage to the structure, and none was found. The aircraft was then ferried to Los Angeles International Airport, where the APU was removed and sent to Delta's APU shop in Atlanta for inspection. As a result of that inspection, during which the engine "...torched on start," it was determined that both the fuel control unit and the gearbox shutoff valve needed to be replaced. Once those units had been replaced, the APU was test run with no further discrepancies.