There was nothing different about the trip Nury Estela Cooperman and her children took to Las Vegas last week except that it was their last.
And no one--not her husband, parents or in-laws--can really say why the former Canoga Park resident wheeled the family's 1989 red Toyota sedan off Interstate 15 outside Barstow, climbed into the back seat, shot her two baby girls in the chest with a .380-caliber pistol and killed herself.
It was her 30th birthday.
The double murder-suicide took place sometime between 10 p.m. and midnight on Sept. 29 on Sidewinder Road, about 20 miles southwest of Barstow, said Dick Ebel, a deputy coroner in San Bernardino County. Cooperman first shot and killed her oldest daughter, Emily, 2 1/2, before shooting Samantha, 1, who lay on her mother's stomach, and then took her own life, Ebel said.
A California Highway Patrol officer who remembers seeing the car parked with its engine running that Wednesday discovered the bodies of Cooperman and her children the next morning.
Linda Kennick, Cooperman's mother-in-law, described her daughter-in-law as "very, very depressed" but declined to provide details. She said Nury had never been treated for depression or any other emotional problems.
Cooperman had left her parents' Burbank home the evening of Sept. 28 bound for Las Vegas, where she lived with Brian Cooperman, her husband of four years. Nury left with the children after an argument with her husband. Earlier news accounts greatly exaggerated the argument, Kennick said.
"They had a small argument on the phone, but everybody fights from time to time," said Kennick. "It wasn't a big thing."
Brian Cooperman, 31, who suffers from high blood pressure, has been under a doctor's care since learning of the death of his family, his mother said. He spoke through his mother in a phone interview on Wednesday.
"They had a lot of opposites, but she grounded him to earth, and he allowed her to see the sky," his mother said, repeating a statement he made to her.
The couple lived for about 18 months with Kennick and her late husband Gary, who died after a long illness in March, 1992, before finding an apartment in Las Vegas about six months ago, Kennick said. Cooperman is general manager of a Las Vegas video distribution company and Nury was a homemaker, Kennick said.
There was nothing about their lives that suggested that she would pull the car over 140 miles outside Burbank and end her life, Kennick said.
"We are devastated by this. It is a nightmare that has gone beyond what a nightmare should be," she said.
Nury's parents, Jose and Nury Perez of Burbank, also were bewildered by their daughter's actions.
"She didn't have any reason to do this, none that I know, that's for sure," said her father, Jose Perez, of Burbank.
Until about two years ago, the Coopermans, who married shortly after meeting while working for the same employer in Burbank, lived at Saticoy Manor, a three-story apartment building in the 21000 block of Saticoy Street in Canoga Park.
They were the model of a young married couple, said Vicki Groom, who manages the 40-unit building.
Groom described the Coopermans as a handsome couple, Nury with her long black hair and ready smile and Brian, a slim friendly man who engaged Groom in casual conversation when they met in the lobby.
"They were nice, outgoing and happy young people," Groom said.
The Las Vegas Metro Police Department, which investigated Nury's failure to arrive home, has closed the case, said Las Vegas Detective John Stewart.
Funeral services for the family will be held at Pierce Brothers Valhalla Mortuary in North Hollywood on Saturday.
Chip Johnson is a Times staff writer and David E. Brady is a special correspondent. Times researcher Dennis Clontz contributed to this story.