Police said a chaotic scene erupted on Saturday night when a gunfire broke out at a biker bar in Iowa, killing at least one person and wounding seven others.
Waterloo Police said about 100 people had gathered outside a building when the confrontation began around 3am.
Officers were at a nearby traffic station at the scene shortly after the shooting started. When they arrived, they found many wounded and others leaving the area.
Firefighters arrived soon after and helped provide medical assistance to the victims.
“It was a very dynamic sight,” said Battalion Commander Ben Petersen of the Waterloo Fire Rescue. “When you get to something like that, you try to measure the patient size and sort the scene.”
Eight were wounded in the shooting, and one died. Four other people were injured by broken glass or debris while trying to leave the area.
No one was arrested during the shooting.
Three people were arrested and charged with disorderly conduct outside the hospital where some of the victims were transferred.