SYLMAR>> A couple and their two young children all died Monday after a fire swept through a home that was not equipped with smoke detectors, fire officials said.

The father, identified by family members as Uriel Estrada, and the children, 12-year-old Isabel and 7-year-old Alejandro Estrada, were pronounced dead at Olive View-UCLA Medical Center not long after being found in the smoke-filled downstairs unit of a detached single-family residence in the rear of a property in the 13800 block of Eldridge Avenue in Sylmar, hospital and fire officials said.

All had been pulled from the first floor of the metal-clad, barn-like structure, which had been converted into a residence, Los Angeles Fire Department spokesman Brian Humphrey said.

The mother of the children, identified by an Olive View-UCLA spokeswoman as 40-year-old Maria Estrada, was initially listed in critical condition, but was also later pronounced dead after she was taken off life support at the wishes of the family, LAFD Captain Jaime Moore confirmed Monday afternoon. Moore said it was likely that the victims died from smoke inhalation although cause of death would be given by Los Angeles County Department of Coroner officials.

The building was approved for occupancy but apparently not equipped with smoke alarms or carbon monoxide detectors, which is the responsibility of the property owner, Moore said.

“If they’d had smoke alarms in there, and this fire was above them, the smoke alarm would have gone off,” Moore said. “They would have woken up and gotten out of there, we would hope, and watched their house burn down — but it would have been just a house.”

An attorney for the property owner, however, said in a television interview that he believes the home was equipped with smoke alarms. The property owner, who wasn’t immediately identified, was being interviewed as part of the investigation, Moore said.

In Los Angeles, fire alarms are required in every sleeping room, in hallways adjacent to those rooms and in any interior stairwells, Humphrey noted.

If violations are confirmed, it’s “absolutely” possible that charges could be filed by the Los Angeles County District Attorney’s Office, Moore said.

“Installation of smoke alarms, installation of carbon monoxide detectors are imperative for the safety of individuals who reside in them, people visiting those occupancies, as well as firefighters who combat fires,” he said.

Arson investigators were at the scene, but officials said there was no indication at this time that the fire was intentionally set. They are looking at various possible causes, including electrical.

The family members, who had previously been living with relatives in Sylmar, were happy that they had just moved into their own place about three months ago, relatives said.

“That was my sister and brother-in-law, and my niece and nephew,” said Alejandro Jimenez, 35, of San Fernando, who was reached by phone Monday afternoon. “I’m at a loss for words. Right now, it’s not real. It’s a bad dream. That’s the bottom line.”

Jimenez described his sister, who worked for a pacemaker manufacturer in Sylmar, as a woman who would work overtime and do anything to help her family. He described Uriel, a former Marine who died Monday on his birthday, as a good man and father, “one of those dads you wish you had.”

As for Isabel and Alejandro, who attended Santa Rosa Bishop Alemany Catholic School, “they were the best kids,” he said, his voice breaking. “They were into sports, into God. They were just amazing.”

Jimenez said that family members had set up a bank account to accept donations to help cover the costs of the Estrada family’s four funerals. The Wells Fargo account number is 607-633-8364.

About 35 firefighters responded to the property at 4:37 a.m. after a call of someone smelling smoke. They noticed the rear building engulfed, forced entry and found the father within feet of the front door. The other family members were “huddled together trying to escape the flames” a bit farther back, Moore said. Firefighters were able to extinguish the blaze in 25 minutes.

As the fire progressed, heavy smoke banked down to the unit below. There was so much smoke inside that “you couldn’t see your hand in front of your face,” Humphrey said.

“We had steady winds of 15 miles per hour, gusting to near 30, fanning the flames and challenging the firefighters, who were undaunted in a well-coordinated and aggressive attack on the fire,” Humphrey said.

Los Angeles Fire Department paramedics performed CPR and advanced life support measures on the family members en route to two local hospitals.

The fire occurred in the barn-like structure, which was permitted by city officials and built in 1965, according to Luke Zamparini, a spokesman for the city’s Building and Safety Department.

In August 2008 the Department of Building and Safety Code Enforcement Bureau issued an order to comply for unapproved construction of an approximately 100 by 120 foot building immediately adjacent to the permitted barn. The order also addressed the open storage of inoperable and/or commercial vehicles. The order had not been complied with to date, Zamparini said.

Maria Estrada’s cousin, Norma Cruz, said they were a fun-loving and “very close knit family that just wanted a better life for themselves.”

“That’s why they moved up here; they thought it was a nice place to live,” Cruz, of Whittier, said outside the home with her children.

Todd Leitz, a public information officer for My Safe LA, was outside the burned home to remind people that they have to be prepared for just these occasions.

Smoke alarms are so inexpensive and readily available and they would have saved the lives of this family, he said.

“We preach the same message; have a plan to get out in case of fire, make the plan, practice it, have at least two ways out of every bedroom, of every house,” Leitz said. “You need to think about it. When you wake up and there’s smoke everywhere, it’s confusing.”

For lifesaving fire and other disaster tips, go to www.mysafela.org.

Staff Writer Rick Orlov contributed to this report.