RCMP said 17-year-old Marie-Hélène Gauvin of Pointe Canot, 18-year-old Tommy Losier and 19-year-old Brian Basque, both of Ste-Rose, and 20-year-old Alexandre McGraw of Losier Settlement died in the crash near Tracadie-Sheila.
Claude Landry, a member of the legislature who represents the area, said the community is in "shock."
"They are grieving and it's a difficult, difficult time," said Landry in an interview on Sunday. "It's a tragedy here."
Community members packed the Saint-Jean-Baptiste and Saint-Joseph Church Sunday morning for a service to pray for the friends and families of the victims, said Landry.
"The church was full," said Landry, who attended the service. "It's a shock to the community.
"Everybody knows everybody down here. The extended families, everybody knows somebody that is related to each family."
The vehicle lost control around 1 a.m. Saturday while driving on an unserviced road off Route 370 near Tracadie-Sheila, about 70 kilometres northeast of Miramichi, RCMP said.
Police said the car slipped off a dirt road in a remote area while trying to go uphill and plunged into the Tracadie River.
Around 3 p.m., tow trucks pulled the submerged vehicle from the river and all four bodies were discovered inside, Cpl. Guy Paul Larocque said Saturday.
Larocque said the car was in the same location where it crashed. He said officials spent hours recovering the vehicle because of its remote location and slippery road conditions.
Police said a crash reconstructionist is involved in the investigation.