The Marion County coroner’s office in Indianapolis identified the victim as Simmie Poetsema, 26, but didn’t immediately release any additional information.
The two other wounded soldiers were conscious, the Defense Ministry said.
The shooting occurred about 3:30 a.m. in Indianapolis’ entertainment district. The Defense Ministry said the three soldiers were from the Commando Corps and were in Indiana for training.
Indianapolis police said they believe some sort of altercation between the three victims and another person or people led to the shooting. No arrests have been made.
The Indiana National Guard said the soldiers had been training at the Muscatatuck Urban Training Center, a 1,000-acre (405-hectare) complex about 70 miles (110 kilometers) southeast of the downtown Indianapolis shooting scene. The Guard said in a statement that the center is used for training by the Department of Defense “as well as other allies.”