For the purposes of this question, 'large-scale riot' is defined as an event of rioting (large-scale disturbance of the peace by a violent crowd) or civil unrest in which any of the following conditions is met:
At least 50 people die due to violence, either due to the actions of rioters or other civilians, or police, military, national guard, or other law enforcement or government agents.
At least 10,000 people are arrested by police, military, national guard, or other law enforcement or government agents.
Property damages are credibly estimated at $1 billion or more. This estimate may come from either the local government of the locality in which the incident takes place, the state government, the federal government, or a major US news publication such as the New York Times, Washington Post, or major broadcast news networks.
Such events should take place in a 100km radius, and within 14 days. As an example, the 1992 LA riots would count, but rioting that is spread across all of California or that occurs in separate phases over a long time period would not count if no single incident met any of the above criteria.
Resolution should cite a government statement or credible news reports that indicate that any of the above conditions have been met by an event of rioting.
