It's been suggested that, as has happened before, the troublemakers causing the violence were actually undercover police.

http://www.globalresearch.ca/index.php?context=viewArticle&code=BUR20100627&articleId=19928

Many were arrested. Conditions were not up to contemporary prison standards.

http://lexgill.com/2010/06/28/urgent-conditions-at-629-eastern-ave-illegal-immoral-dangerous/