The National Transportation Safety Board (NTSB) released its preliminary report into what caused a door plug to detach from the fuselage of a Boeing 737 Max 9 jet at 16,000 feet, leaving a gaping hole in the plane. The jet, operated by Alaska Airlines, was carrying 171 passengers at the time, making a short flight between Portland, Ore., and Ontario, Calif., on the evening of Jan. 5. The hole left by the door plug led to a rapid depressurization of the plane, injuring one flight attendant and seven passengers. Records gathered over the course of the NTSB’s investigation indicate that four bolts that were intended to help secure the door plug to the plane were not reattached after the plug underwent repair work at Boeing’s Renton factory. The bolts keep the door plug from moving vertically. Read more: https://www.king5.com/article/tech/science/aerospace/boeing/ntsb-preliminary-report-boeing-737-max-9-incident-alaska-airlines-flight-1282/281-1d0975c3-d658-4867-ab3a-b260ab5fe494