Given the task definition, example input & output, solve the new input case.
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.
Example: This list contains the top 25 accounts with the most followers on the social photo-sharing platform Instagram. As of May 2018, the most followed user is Instagram's own account, with over 235 million followers. Selena Gomez is the most followed individual, with over 137 million followers. Ten accounts have exceeded 100 million followers on the site.
Output: who has the maximum number of followers on instagram
The answer is talking about the Instagram accounts that have the most followers. The question asking about the maximum number of followers. So this is a good example.

New input case for you: 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