A man who opened fire on police with a shotgun was killed as two officers returned fire at a suburban Chicago home where two more people were found to have been shot earlier, one of them fatally, police said.

The two officers, called to the house in a normally quiet, tree-lined neighborhood in the village of River Forest, just west of Chicago, were ambushed at the door by the suspect, said the town’s deputy police chief, James O’Shea.

Both officers were treated at a nearby hospital for non-life-threatening injuries. One was struck by a round in his body armor, O’Shea said.

The gunman, reported by Chicago-area media to be 24 years old, was killed in the ensuing shootout.

Neighbors told television news outlets they heard 20 to 30 shots fired. One man who lives next door described how he saw one of officers stumble behind a tree before shooting into the house following the initial gunshot.

Officers entering the home later found two people who had apparently been shot by the suspect before police arrived — a 60-year-old man declared dead at the scene and a 59-year-old woman who survived with gunshot wounds and other unspecified injuries, O’Shea said.

Chicago-area media reported that the woman, believed to be the assailant’s mother, was hospitalized in critical condition.

There was no word on a possible motive for the violence, and police declined to immediately release any further information about the shootings.