"We're a community of about 950 people and virtually everybody knows most of the people involved," said Cape St. George Mayor Peter Fenwick.
"It's a terrible shock to a small community like this."
The RCMP say they responded to a shooting at the De Grau Medical Clinic just before 1 p.m. in De Grau on the province's Port au Port Peninsula.
The Mounties say a 49-year-old woman was killed and a 54-year-old man who was injured later died at the Sir Thomas Roddick Hospital in Stephenville, N.L.
RCMP Sgt. Marc Coulombe said investigators are not looking for a suspect, but he wasn't able to release any details of the circumstances surrounding the shooting.
But Fenwick and a neighbour and relative who did not wish to be identified said the deceased are Stephanie Chaisson and her estranged husband Luke Chaisson. They said the couple had two grown children, a son and daughter.
Stephanie Chaisson had worked at the clinic near her home for years, said the neighbour who did not wish to be named. Luke Chaisson previously worked at the nearby Lower Cove Mines, said the neighbour.
"They were friends of ours and we loved them both. They're both gone now, and it shouldn't have happened.
"I'm just devastated."
Provincial politician Tony Cornect, who represents the district of Port au Port, was born in De Grau.
"It's a very sad day," he said, expressing his condolences to the family.
Fenwick said Luke Chaisson had lived in the community for most of his life and had many relatives in the region.
"It's almost like a death in the family."