An unemployed Los Angeles father said in a suicide note that he methodically shot and killed his family before turning the gun on himself because he and his wife were fired by the hospital where they worked after being told "you should have blown your brains out."
But the hospital said it was "confident" that none of its employees told Ervin Lupoe to take his own life or kill his family.
Police are investigating after finding a horrific scene at the Lupoes' home in Wilmington, Calif., on Tuesday morning.
In one upstairs bedroom, the bodies of twin 2-year-old boys were found beside their dead mother. In another bedroom, 5-year-old twin girls and their 8-year-old sister lay next to their lifeless father.
Lupoe and his wife had both recently been fired from their jobs at Kaiser Permanente West Los Angeles Medical Center.
His letter, faxed to KABC-TV in Los Angeles, indicated that Lupoe and his wife — both 40 — had been investigated for misrepresenting their employment to an outside agency to obtain child care, and claimed that an administrator told the couple on Dec. 23: "You should not even had bothered to come to work today. You should have blown your brains out."
The letter said the couple complained to the hospital's human resources department and eventually were offered an apology, but two days later they were fired.
"They did nothing to the manager who stated such and did not attempt to assist us in the matter, knowing we have no job and five children under 8 years with no place to go. So here we are," the note said.
In a statement, the hospital said they were "saddened by the despair in Mr. Lupoe's letter faxed to the media, but we are confident that no one told him to take his own life or the lives of his family."
When asked what the couple was offered an apology for and whether an administrator said what Lupoe alleged, hospital spokesman Anthony Crump told FOXNews.com he could not comment on employee matters.
The Los Angeles Police Department said it's unlikely the medical center would be held legally responsible for telling Lupoe to blow his brains out.
"I don't know how someone's statement could be prosecuted," LAPD Officer Sam Park told FOXNews.com. "It's just like if I told you to go jump off a cliff. I don't think it could be prosecuted legally."
Park said he wasn't aware of any investigation into the hospital or its employees.
Police believe Ervin Lupoe killed his five children and his wife before turning the gun on himself.
"Why leave our children in someone else's hands?" Lupoe wrote in his letter to KABC. The station posted the letter on its Web site with parts redacted.
The station called authorities after receiving the fax and a phone call from Lupoe, and a police dispatch center also received a call from a man who said, "I just returned home and my whole family's been shot." Police are unsure who the male caller was, but they suspect it was the father.
Officers rushed to the home in Wilmington, a small community between the ports of Los Angeles and Long Beach, about 8:30 a.m. Tuesday and found the bodies.
All the victims were shot in the head, some multiple times, coroner's Assistant Chief Ed Winter said. The killings may have occurred between Monday evening and early Tuesday, based on neighbors' accounts of firecracker sounds, he said.
Although the fax — addressed to "whom it may concern" and explaining "why we are dead" — asserted that the wife, Ana Lupoe, planned the killings of the whole family, police Lt. John Romero said Ervin Lupoe was the suspect. A revolver was found next to his body.
It was the fifth mass death of a Southern California family by murder or suicide in a year. Police urged those facing tough economic times to get help rather than resort to violence.
"Today our worst fear was realized," said Deputy Chief Kenneth Garner. "It's just not a solution. There's just so many ways you find alternatives to doing something so horrific and drastic as this."
Ervin Lupoe removed three of the children from school about a week and a half ago, saying the family was moving to Kansas, the principal told KCAL-TV. Crescent Heights Elementary School Principal Cherise Pounders-Caver said nothing seemed to be troubling Ervin Lupoe, and she did not ask why the family was moving.
Kaiser Permanente Medical Center West Los Angeles released a statement confirming Lupoe and his wife were fired as medical technicians more than a week ago. The hospital said the firings followed an internal investigation but would not specify why they lost their jobs.
Lupoe's fax identified his children as Brittney, 8; 5-year-old twins Jaszmin and Jassely; and twins Benjamin and Christian, ages 2 years and 4 months. Winter confirmed the identities of the girls, but the boys' names were pending.
To Amanda Garcia, everything seemed normal in the Lupoe house next door. Her neighbors always had a friendly wave and their five young children would play outside.
"They were happy, they had birthday parties," the 22-year-old Garcia said as she choked back tears near her home. "The kids were always outside on bikes, riding on their wagon."
FOXNews.com's Michelle Maskaly and The Associated Press contributed to this report.