In 1938, Morton was stabbed by a friend of the Music Box's owner and suffered wounds to the head and chest. A nearby whites-only hospital refused to treat him, as the city had racially segregated facilities. He was transported to a black hospital farther away. When he was in the hospital, doctors left ice on his wounds for several hours before attending to the injury. His recovery from his wounds was incomplete, and thereafter he was often ill and became short of breath easily. After this incident, his wife Mabel demanded they leave Washington. Worsening asthma sent him to a hospital in New York for three months. He continued to suffer from respiratory problems when he travelled to Los Angeles with the intent to restart his career. He died on July 10, 1941, after an eleven-day stay in Los Angeles County General Hospital.