From the Daily Beast:
Through media reports, the Brady Campaign to Prevent Gun Violence, a nonprofit lobbying group, has compiled a list of 431 shootings with more than one victim since 2005. On average, according to the organization, a multiple-victim shooting happens every 5.9 days in the United States. The deadliest city in this period, according to the data, is Chicago, with 17 shootings since 2005—totaling 72 people wounded and 30 deaths. Thirteen of those shootings were in a public place. New Orleans, Kansas City, and Philadelphia were tied for second bloodiest, with nine shootings in this seven-year period.
View the data, an interactive map an the full post: Interactive Map: The U.S. Shooting Epidemic