PORT ST. LUCIE, Fla. (CBS12) — Multiple 911 calls sent officers rushing to a Port St. Lucie neighborhood at 3:30 a.m. Sunday, where police say an argument over a key ended with two men killed in a shootout.

Officers with the Port St. Lucie Police Department say the shooting happened outside a home located at 1366 SE Rivergreen Circle.

According to investigators, several people called 911 reporting shots fired.

Neighbor Wanda O’Neil said she was getting ready for bed when she heard several rounds of gunfire.

“I just heard the bang, bang, bang and I said, ‘Oh, what was that?’ I thought I heard a woman talking; it wasn’t yelling or screaming or anything,” she said. “Then I heard bang, bang, bang again and it stopped.”

Upon arrival, police say they found Carl Loubeau, 24, and Juliun Stokes, 22, suffering multiple gunshot wounds in the driveway of a home.

Both men were reportedly transported to the hospital, where they later succumbed to their injuries.

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An investigation revealed the two men had been socializing with friends earlier that night before returning to the home on SE Rivergreen Circle, where an argument ensued.

The fight was allegedly about house keys and entering the home when things escalated into a shootout.

O’Neil has been living in the Rivergreen Villas neighborhood for 17 years and describes it as quiet.

“We’ve never had anything like this before,” O’Neil said. “This is kind of scary because this is three doors down from me.”

Police say the incident is isolated, and all parties involved are detained and cooperating with the investigation.

Anyone with information regarding this incident who has not yet spoken with detectives is encouraged to contact the Port St. Lucie Police Department at 772-871-5000.

Port St. Lucie Police Chief is expected to hold a news conference Monday to release additional information. A time for the briefing has not yet been announced.

This is a developing story. Check back for updates. As we learn more, we will keep you posted.