Detroit:

Jobs expanded so rapidly that 400,000 people were attracted to the city from 1941 to 1943, including 50,000 blacks in the second wave of the Great Migration, and 350,000 whites, many of them from the South. Some European immigrants and their descendants feared black competition for jobs and housing. The federal government prohibited discrimination in defense work but when in June 1943, Packard promoted three blacks to work next to whites on its assembly lines, 25,000 whites walked off the job. The Detroit race riot of 1943 took place three weeks after the Packard plant protest. Over the course of three days, 34 people were killed, of whom 25 were African American, and approximately 600 were injured, 75% black people.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". After which event did the 1943 race riot happen?
Packard plant protest