Cindy Bizier fretted incessantly about her grandson’s care, worried the boy would chase his yellow dump truck into the street or burn himself with his mother’s lighter or wander too close to the canal while his mother, Autumn, who struggled with drugs, wasn’t watching.

So the anguished grandmother did something extraordinary: She called child welfare authorities on her own daughter. More than once. And when a child-abuse investigator visited the Sunrise home where the three generations lived, Bizier stepped outside and quietly pleaded with him to take Aidan into foster care. It was the only way, she believed, to protect the boy she lovingly called Charlie Brown.

Five calls to the Department of Children & Family’s hotline prompted five investigations that resulted in parenting classes and failed drug treatment for Autumn Bizier.

Aidan would die in a house fire ignited while Cindy was at work and Autumn was asleep, a state death report said. Firefighters found the boy on the garage floor near the door, his teddy bear under his left arm, his lifeless dog, Missy, by his side. Vincent Lee “Aidan” Bizier was just 3.

“I should have done something. I should have been stronger. Tougher,’’ said Cindy Bizier, 56, her eyes welling with tears. “He needed to be in a safe space. I figured God took him because we weren’t good.’’

If a blazing fire was the cause of death, puzzling decisions by state lawyers played a role.

Twice in the months before Aidan’s death, investigators with the Broward Sheriff’s Office, which handles the county’s child-abuse investigations, had asked their lawyers to petition a judge to order Autumn to accept help from the state or to remove the boy from her care. Both times the lawyers refused, saying they did not have cause.

The Miami Herald studied six years of records detailing the deaths of children whose families were known to DCF and found that when investigators or doctors paid to recognize abuse want a child to be removed, or for a judge to order other forms of protection, agency lawyers often stand in the way. They cite a lack of “legal sufficiency.”

Aidan was among at least 49 Florida children who died after child welfare lawyers said the state lacked authority to act either on their behalf, or on behalf of a sibling.

In Florida, the state must file a court petition before a judge can either place a child in state care or order the parents to accept services and oversight. Otherwise, everything is voluntary. DCF lawyers and their proxies at the attorney general’s office in several counties are the gatekeepers, deciding whether and when to file.

Under federal laws that govern most of Florida’s child welfare dollars, investigators and their attorneys must make “reasonable efforts” — such as parenting classes or drug treatment — to keep children with their families when the youngsters are at risk of harm.

But the rules are different when children have already been seriously hurt. Florida law does not require “reasonable efforts” when a child has experienced “aggravated child abuse” or when their parents’ “extensive, abusive, and chronic use of alcohol or a controlled substance,” mental illness or other serious dysfunction renders them unfit.

DCF’s interim secretary, Esther Jacobo, said reserving foster care for only the most intractable cases is not only the law, it is also prudent. “All child welfare systems have that as their tenet,” she said.

But some children’s advocates say administrators in Florida have defined “reasonable efforts” so broadly that it leaves children in danger.

“Reasonable efforts should never mean that you leave a child in a dangerous situation and cross your fingers,” said Jess McDonald, who led the Illinois Department of Children and Family Services from 1994 to 2003, and now is helping oversee reforms in Washington state.

“Reasonable efforts do not trump child safety,” said Linda Spears, vice president of policy for the Child Welfare League of America. “If that were the case, there would be no point in having a child protection response.”

Seven months after Aidan’s March 2009 death, the top administrator of Miami’s private child welfare agency, Fran Allegra, complained in an email broadside at agency lawyers that investigators feel they “do not have the freedom and autonomy to make professional decisions.”

Two of DCF’s top administrators — then-Children’s Legal Services Director Mary Cagle and Assistant Secretary Pete Digre — wrote in a 2010 memo that “legal sufficiency” ought to be one standard applied by the state, but that front-line workers should also use “common sense.”

Even when parents repeatedly violated court orders intended to protect children, DCF lawyers sometimes stymied efforts to intervene. In February 2009, for example, DCF removed newborn Lucas Daniel Machin-Torres and his two siblings from their mother’s custody in Homestead; Jocelynn Torres-Machin’s untreated bipolar disorder and “violent outbursts” had rendered her unfit, DCF argued.

In one reported incident leading up to the removal, Torres-Machin absconded with three children unrestrained in a two-seat rented Ferrari. Her mother-in-law, trying to stop Torres-Machin from speeding off, broke her wrist when Torres-Machin allegedly grabbed her by the hair, threw her to the ground, punched and kicked her. She was later arrested driving 112 miles per hour on Biscayne Boulevard.

Under the judge’s order, Torres-Machin could see her children only under the supervision of her husband, Gregorio Machin, with whom she and the children lived. The abuse reports continued.

December 2009: The family was violating the court order and leaving the children with their “very violent” mom.

May 2010: Torres-Machin allegedly punched one of her children in the eye.

March 2011: The father again violated the court order, and left the children with their mom, who then left them home alone.

Following the March 2011 report, investigators consulted their lawyer, who told them only to “reiterate the conditions of the custody order” to the father.

On April 15, 2012, Torres-Machin took her children to a swimming pool. One of her sons told investigators she had spent the day going back and forth to a bathroom, he believed, to snort cocaine. Lucas, left unsupervised, nearly drowned. He was disconnected from life support seven days later, on April 22.

In a December 2012 email, court-appointed psychologist Vanessa Archer lamented that “Lucas’ death should never have happened.”

“I very much doubt that any internal review of the case is going to hold anyone truly accountable,” Archer wrote a month later. And she was right: A death review concluded “the children’s safety and well-being were appropriately addressed.”

Some reviews are more critical, including one involving the Tampa-area death of Ezekiel Mathis. In May 2011, lawyers approved moving to the 2-year-old girl, believing she had been abused by her mother’s boyfriend, but forbade the agency from seeking to remove Ezekiel, her infant brother. The girl had unexplained bruises over much of her body. Because Ezekiel showed no obvious signs of abuse, he was left in the home.

His mother signed a safety plan forbidding the boyfriend, Damarcus Kirkland-Williams, from contact with the boy. The couple would renege on the promise.

Twice, DCF investigators asked for the go-ahead from lawyers to seek removal of Ezekiel from the home. Twice, they were turned down by the Florida attorney general’s office, which said they lacked cause. Citing “serious concern,” Hillsborough County Circuit Judge Tracy Sheehan tried to step in on Ezekiel’s behalf, ordering that Kirkland-Williams have no contact with the boy. But she had no authority to do that, DCF’s subsequent review of the case acknowledged, because the agency had not filed a petition on his behalf.

A caseworker visited the home on May 18, 2011, and found Kirkland-Williams present. Ezekiel’s mother acknowledged he had been there on several occasions, safety plan or no. Hours after the caseworker left, Kirkland-Williams attacked Ezekiel, police said, slinging him into a dresser because he was upset with the boy’s mother. When Ezekiel began to cry, Kirkland-Williams allegedly placed him on his face-down and struck him twice in the back. He died of his injuries, just 13 months old. Kirkland-Williams is charged with first-degree murder and child abuse.

After Ezekiel’s death, Florida Attorney General Pam Bondi ordered an internal review, which found flaws in the way lawyers had handled the case. What the lawyers lacked, the 15-page report said, was the “whole picture” of Ezekiel’s troubled family. The lawyers also “did not give sufficient deference to the opinions” of investigators who had actually seen Ezekiel and his mother.

Jacobo said her agency’s lawyers are now being trained to look at the entire family dynamic and that child protection investigators should feel empowered to push back when they are uncomfortable with a decision by their attorneys. She said the agency has a conflict-resolution procedure for use when lawyers and child protection professionals are at odds. But in many cases, lawyers still hold sway. Aidan’s case is an example.

Over a two-year stretch, BSO concluded that Aidan’s safety was at risk as long as his mother was in charge and still using drugs. Cindy Bizier shared the same fears, even threatening in early 2009, two months before the boy’s death, to shut off her own electricity and stop buying food to force DCF to shelter the boy. Among the allegations:

March 12, 2008: Then-2-year-old Aidan was found wandering alone on the bank of a canal. Both Autumn and her then-boyfriend, Shane Howard — not Aidan’s birth father — acknowledged using marijuana; Howard tested positive for marijuana, the anxiety drug benzodiazepine and cocaine.

Though a BSO investigator wanted to go to court to force Autumn and Howard to better protect the child, DCF lawyers declined. “There is limited neglect to the children documented thus far,” a report said.

December 4, 2008: DCF was told Autumn and Howard abused drugs “regularly” — which the couple acknowledged. She also was accused of driving her car while under the influence of drugs with Aidan in the car. “The parents’ protection of the children is questionable, considering they continue to use illegal substances,” an investigator wrote. The investigator tried to file a court petition to force Autumn to accept help from the state, but DCF lawyers said there was not enough evidence.

Jan. 8, 2009: Autumn denied an allegation that she took Aidan with her to shoplift from stores. An investigator was “concerned about the safety of the child due to the mother’s drug habit seemingly becoming worse” and suspected Aidan was being brought along by Autumn during her drug purchases. DCF lawyers again blocked BSO from filing a court petition.

Autumn Bizier insists her actions never endangered her son. “DCF did come to the house a couple of times and they looked at Aidan and said he was healthy and looked fine and there was food in the house,” she said. “I was a young mom, but that did not stop me from doing what I needed to do to take care of my son.”

On the morning of March 13, 2009, Cindy Bizier received a panicked phone call from Autumn. The grandmother rushed home. As she got closer, she saw a helicopter hovering overhead. She knew.

A neighbor had tried to charge in, but was pushed back by the flames. In addition to Aidan and Missy, a pit bull, two Shar-Peis and a mixed-breed dog also died. Firefighters believe Aidan was playing with a Zippo lighter when the fire started. The death was ruled an accident.

Though Autumn tested positive for marijuana and said she had smoked pot the night before, the Broward state attorney’s office determined Aidan’s death was an accident and declined to press charges.

The flames left an eerie, heart-shaped scorch mark on the wall of the garage, precisely where Aidan was found, alone except for Missy, the faithful pet who died beside him.

Haunted by the loss of her grandson, Cindy Bizier couldn’t bring herself to paint it over.