You will be given a definition of a task first, then some input of the task.
In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.

The 1967 Detroit riot, also known as the 12th Street riot or the 1967 Detroit rebellion, was one of 159 race riots that swept cities in the United States during the 'Long hot summer of 1967'. This riot was a violent public disorder that turned into a civil disturbance in Detroit, Michigan. It began in the early morning hours of Sunday July 23, 1967. The precipitating event was a police raid of an unlicensed, after-hours bar then known as a blind pig, just north of the corner of 12th Street (today Rosa Parks Boulevard) and Virginia Park Avenue, on the city's Near West Side. Police confrontations with patrons and observers on the street evolved into one of the deadliest and most destructive riots in the history of the United States, lasting five days and surpassing the violence and property destruction of Detroit's 1943 race riot just 24 years earlier.
Output:
what started the riot in detroit in 1967