HAMMOND, Ind. (WLS) — A person of interest is in custody after five people were shot, two fatally, at a Northwest Indiana pub early Sunday morning, police said.

Hammond police officers responded to reports of gunfire at Portside Pub at 1516 Indianapolis Boulevard around 4 a.m.

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There, responding officers found five gunshot victims. Two died at the scene.

ABC7 is told that one of the victims who died was a man who worked at the pub as a bartender. The other was a woman, who family members identified as Lorraine Reyna.

“All of us come here. We were going to celebrate a birthday here, today,” said Johnny Jernigan, Reyna’s close friend. “It’s very far from a celebration. I’m very, very, very mad.”

Four of the people shot were trying to help someone involved in a domestic situation, but “their heroic efforts to stop the situation from escalating were met with violence,” police said in a press release.

“This didn’t have to happen. I can’t believe it,” Jernigan said.

Hammond Mayor Thomas McDermott said the domestic dispute started in the parking lot.

“They were good Samaritans, simply trying to break up a domestic situation, and they lost their lives because of it,” McDermott said.

Three people were taken to local hospitals, police said. Two of them are in serious condition, and another is stable.

Paola Gaeta showed up to the scene in search of her brother before finding out he was among those injured.

“I can’t reach him. My brother’s car is still here,” Gaeta said. “But he was, like, at the wrong place at the wrong time.”

One southbound lane of Indianapolis Boulevard was temporarily closed as officers investigated.

“It’s so disheartening. This gun violence has to stop,” said Angelica Negron-Jernigan, Reyna’s close friend.’

Police the name of the person of interest will be released after formal charges are filed. Investigators believe there is no threat to the public.

Flowers now adorn the bullet-riddled front door of the pub.

Police asked anyone with information to contact them at 219-852-2906.

Authorities did not immediately provide further information.