A tragic incident unfolded in Cicero, Illinois, where a teenage boy was fatally shot during an attempted robbery on Wednesday afternoon, according to local officials.

The confrontation occurred around 3:20 p.m. in the 1300 block of South 58th Avenue, where two teenagers had arranged to meet for a marketplace exchange initiated through social media, officials reported.

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The intended sale fell through, and as the teen attempting to sell an item began to leave, the other teen confronted him, attempting to seize the item, authorities stated.

During the struggle, a relative of the teen selling the item intervened, exiting a nearby vehicle. The alleged robber then shot the relative twice. In response, the relative, who was armed, fired back, striking the robber once, according to officials.

For related news, see: Downtown shooting leaves man wounded, Chicago police say

The relative was taken to Loyola University Medical Center, where he remained stable.

A short time later, a teen believed to be the alleged robber came into Rush Oak Park Hospital with a gunshot wound; he later died, officials said.

The Cook County Medical Examiner’s Office identified the teen killed as Angel Dominguez.

Police are investigating and said the police department is a designated safe place to conduct marketplace transactions.

This is a developing story; check back with ABC7 Chicago for updates.