Fire investigators were unable to say what sparked the blaze at 535 E. 41st St., in a quiet well-kept neighborhood. But they said they consider it suspicious.
Marie Auguste, 43, suffered burns over 30 percent of her body and was in critical condition in Jackson Memorial Hospital in Miami. Her 13-year-old son who survived was in good condition in Miami Children's Hospital.
It was the deadliest fire in South Florida since October 1998, when a mother and her three children were killed in a fire in northwest Miami-Dade County.
Police said Sunday's fire started about 12:30 a.m. in the front of the family's four-bedroom home, near the front door in a living room area, but they were unable to say what ignited it.
"I can't rule out that it was intentional," Police Homicide Lt. Ralph Gracia said. He added that an electrical box and a metal door were taken from the home to a crime lab to be inspected.
Contributing to the tragedy: Rescuers could not gain immediate access because of the iron bars intended to secure the pink stucco, one-story home, Gracia said. The bars likely made escape impossible for the trapped children, he added.
Three of the victims, a 17-year-old boy and his sisters, 12 and 6, were in one bedroom. The 6-month-old girl had been in her mother's bedroom.
All died from smoke inhalation and were severely burned. The 17-year-old boy was pulled out but died at Jackson Memorial Hospital, Gracia said.
All were asleep when the fire broke out except for the 13-year-old survivor, who was dozing off while alone in a separate room. He heard glass breaking from the heat of the fire, Gracia said.
Police did not release the children's names because the mother was unable to talk to police and give permission. Two other women who rented small efficiency units on the home's eastern side were not injured.
Gracia said the 13-year-old boy told them he and his mother fled through a back door while flames engulfed the home, where the family has lived since November 2001.
After they were outside, the boy said, he and his mother ran to the front of the house screaming for help. A neighbor called 911, police said.
Julio Alarcon, who was visiting relatives in the house across the street, said he was sleeping shortly before 1 a.m. when the frantic sound of honking horns awakened him.
"The flames were coming out of the house 20 feet high," Alarcon said. "The lady was running back and forth trying to reach the kids. She was screaming, `The kids are inside, please help me!'"
Alarcon said Auguste appeared to have been burned and that some of her nightgown had melted onto her skin. He said he was unable to help her because the gate in front of the home where he was staying was padlocked shut.
"It's terrible. I wanted to scream because I couldn't do anything," he said. "In my mind I see the kids coming out in the firemen's arms."
Two other men stopped and aimed garden hoses at the house.
The Hialeah Fire Department received the call for help at 12:48 a.m. and was on the scene six minutes later, Hialeah Police spokesman Jose Caragol said.
"The fire was so intense, and the flames were in the front of the house," Caragol said. "They had to cut into the front gate, which had been deformed by the fire. Once they tried to get in, the fire was so incredible."
Adelina Peratto, who rented an efficiency on the home's east side, said she was awakened by the smell of smoke and thought her apartment was on fire. She ran outside to safety, but said the fire's intensity prevented her from helping anyone else.
"I was so scared," Peratto said. "I couldn't do anything. It was such a huge feeling of helplessness."
Xiomara Eyan, next-door neighbor to the house that burned, said police banged on her door about 1 a.m., yelling for her to get out.
Outside, she said, she saw fire-rescue workers performing CPR on one of the boys and another boy being taken away in an ambulance. She said Auguste was "screaming in front of the house."
Eyan said Auguste seemed devoted to the children. "I feel bad that so many children suffered," she added.
Police were trying to contact the 13-year-old's father on Sunday to notify him of the tragedy. If the father cannot be found, the boy will be put in custody of the Florida Department of Children & Families, Gracia said.
Records from the Florida Department of Corrections show that Auguste was convicted in 1985 of aggravated child abuse and was sentenced to five years of probation. Details of the case were unavailable Sunday.
Court records also show she was awarded $1.5 million in February 2001 in a medical malpractice suit she filed against the Economic Opportunity Health Center after her daughter Rose Auguste was born with an injured shoulder. Auguste alleged negligence on the part of the doctor and midwives involved in the birth.
Miami-Dade County records show the home was in both Auguste's and the child's name.
Police said DCF removed children from the home about two months ago, and they were returned days later, but could not say why they were removed. DCF officials would not comment.
Researchers Cindy Kent and Tracy Ahringer contributed to this report.
