An American Airlines Boeing 737 Max 8 aircraft from Los Angeles lands at Washington Reagan National Airport in Washington D.C., the United States on March 13, 2019. The United States is grounding all Boeing 737 Max 8 and 9 aircraft, said U.S. President Donald Trump Wednesday, as the country becomes the last major country to do so after two crashes by the model in recent months. (Xinhua/Ting Shen)