More than 1,000 people attended a block party and car show with live music at Ilous Ellis Park in Fort Pierce, north of West Palm Beach, Florida.
Around 5:20 p.m. multiple gunshots rang out and sent attendees scrambling for safety.
In addition to the shooting victims, multiple people were injured including a child.
Chief Deputy Brian Hester, who took part in the parade, told reporters on Monday night, “It was mass chaos. People were running in all different directions.”
“There were people laying behind cars, laying behind anything they could lay behind. It was kind of hard to tell who was a victim and who was just hiding at that point.”
Detectives believe the shooting at the MLK Day event was sparked by a dispute between two parties at the park.
“Sounds like, from our initial investigation here on scene, there was a disagreement of some sort between two parties and, unfortunately, they chose to resolve that with guns,” Hester said. “It’s really unfortunate and it’s sad that during a celebration of someone who represented peace and equality that a disagreement results in a use of guns and violence.”
Watch the ABC News report via “Good Morning America” below.
Anyone with information on the incident at the MLK Day event is urged to call the St. Lucie County Sheriff’s Office at 772-462-7300 or contact Treasure Coast Crime Stoppers anonymously at 1-800-273-8477.