The shooting happened around 7:25 p.m. in the 1000 block of 177th Street in Hammond, police said.
A 16-year-old boy was found at the scene with a gunshot wound.
The victim was taken to a local hospital in Munster in critical condition, and he later died, police said.
The boy's identity has not been released.
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No information about a suspect was available as Hammond police continue to investigate.