Table showing mass shootings by city in the decade from 2013 to 2023. The cities most affected by mass shootings are as follows: 1) Chicago 2) Philadelphia 3) Baltimore 4) Houston 5) Saint Louis 6) New Orleans 7) Washington 8) Memphis 9) Detroit and 10) Brooklyn. The issue in Chicago, however, is notably worse, with more mass shootings than the next three cities combined.