NEW ORLEANS — Gunshots erupted in a crowd of bead-wearing, drink-carrying late-night revelers on Bourbon Street during the countdown to Mardi Gras, wounding four people and sending bystanders running and screaming. Hours later Sunday, though, the same stretch was packed with partiers who said they weren’t letting the violence dampen their fun.

In a video taken by a witness Saturday night and released the next day, the shootings are preceded by footage of people standing shoulder to shoulder in New Orleans’ famed tourist district, with some holding green plastic cups and wearing gaudy hats or masks.