The La Porte County Coroner's Office said Javon Townsend was shot three times and died at Franciscan Hospital in Michigan City.
The shooting happened at about 11 p.m. at a home in the 1700-block of Liberty Avenue in Pine Township, just outside Michigan City, according to Porter County sheriff's police.
An 18-year-old woman and another male juvenile were injured in the shooting. They were taken to a hospital in Chicago, and their conditions were not known.
Shocked neighbors say chaos erupted moments after someone opened fire on a house where there was an apparent after-prom party going on.
"You know, they're running towards 20. They're running towards 12," witness Michael Schnell said. "They ran behind my house in the back."
Neighbors say the owner of the residence where the shooting happened often rents out the house to vacationers.
Schnell says he and his neighbor heard what sounded like fireworks before shots rang out and bullets began to fly.
"And then there was one lady, who actually went by Kim's garbage cans, was sobbing uncontrollably," Schnell said. "So must have been somebody related to something that was shot and she was, she was crying, sobbing for an hour."
The gunfire shattered windows of neighboring homes, too, but didn't hurt anyone else.
Officials with Michigan City Area Schools said the celebration was a post-prom party following prom activities.
"Michigan City Area Schools is aware of the tragic off-campus incident involving several Michigan City High School students following prom activities," Michigan City Area Schools said in a statement. "Our thoughts are with the students, families, and everyone impacted during this difficult time. Counseling and support resources will be available to our students and staff."
Police said the shooting was believed to be an isolated incident.
No other information was available.
Anyone with information regarding the shooting is urged to contact police.
The video in the player above is from an earlier report.