(CNN)Two people were killed and three others injured Friday in Missouri when gunfire erupted at a gathering in the St. Louis County city of Kinloch, police said.
Willoid Williams told CNN affiliate KMOV that he was in the area for a "neighborhood celebration" at a park that started "peaceful and beautiful" and then turned violent. The gatherings have been happening since the 1990s.
Officers who responded about 6:30 p.m. were told "five adult male victims had self transported to area hospitals," according to St. Louis County Police.
Two victims were pronounced dead at a hospital and three others sustained non-life threatening injuries, police said in a statement.
Williams told the station that a truck pulled up near the park -- about 12 miles northwest of St. Louis -- and at least three people "just started shooting." Williams said he watched from his truck.
"I saw people falling, scattering and scrambling," he said.
Police said the shooting is under investigation and no other details were provided. On Friday night, officers and detectives looked for clues in the patches of grass around abandoned picnic tables, according to news footage.