Six-month old Rosalyn Ramos — whose lifeless body was discovered by her 5-year-old brother in the back seat of daddy’s car — is the 29th child in the United States to die alone inside a hot vehicle so far this year. Three of these deaths were in South Florida.

Their father, Lazaro Ramos, was not usually the parent who took the kids to school.

On Tuesday, he strapped his baby daughter into her rear-facing car seat and made sure her brother was buckled in beside her. He dropped the boy off at Doral Academy Preparatory School, but instead of taking his baby daughter to the day-care center, he continued on to work, forgetting she was in the back seat.

Nine hours later, he returned to pick up his son, who discovered his baby sister’s tiny body, Miami-Dade police said.

Ramos told detectives it was not part of his routine to care for the baby. He was brought in for questioning, but no charges were expected to be filed Wednesday.

Neighbors described Ramos as a doting father who adored his “ muñequita,” or “little doll,” as the parents called baby Rosalyn.

“I’m sure the family is destroyed,” said Ana Arias, a neighbor. “They were obsessed with this little girl. They were crazy about her.”

Arias and other neighbors said that Lazaro Ramos had been living with the baby’s mother and her parents for more than a year in an apartment on Northwest 87th Avenue in Doral. Ramos’ 5-year-old son was from a previous relationship.

Incidents like this are alarmingly common with all the distractions of modern life, experts say. Nationwide, there have been more than 550 such cases since 1998. Florida is second only to Texas in the number of these deaths.

“This is not something that these families ever recover from,” said Amber Rollins, the director of Kids and Cars, a Kansas-based organization for the prevention of non-traffic, car-related deaths. “There’s nothing worse than the death of a child, but when a parent — the person who loves them most — is responsible, that’s the only thing that could be worse.”

Rollins said even the most loving, responsible parents can experience momentary child-care lapses. Parents of young children are under an enormous amount of stress, and often do not get enough sleep, which “changes the way the brain functions,” she said.

As was the case with Tuesday’s tragedy, “the No. 1 factor is the change in a daily routine,” Rollins said.

Willful negligence accounts for a small percentage of child deaths in hot cars, according to Malvina Duncan, the coordinator of Safe Kids Miami-Dade, a prevention organization associated with Miami Children’s Hospital.

“In more than half of these cases, the child is simply forgotten by a distracted parent or caregiver,” Duncan said. She said there is “no typical profile” of parents who forget their children, and people of “all socioeconomic backgrounds” experience such distractions.

Duncan said that when the body temperature of a child reaches 104 degrees, internal organs begin to shut down; at 107 degrees, the condition can be deadly. If a child is asleep or unattended, the warning signs go unnoticed.

“Because they’re children, they are three to five times more likely to suffer hyperthermia because their regulatory systems are immature,” she said.

A study by San Francisco State University showed that more than half of the deaths from hyperthermia, or heat stroke, since 1998 have been of children under the age of 2.

Rollins said this “preventable tragedy” has become more common since the 1990s, when cars came equipped with airbags that could kill children sitting in the front seat. Now, rear-facing car seats are recommended for infants, which “look the same whether there is a child in there or not,” Rollins said.

For each fatality that is investigated by the police, experts estimate there are hundreds of “near misses” that go unreported.

It is illegal in Florida to leave a child unattended in a car for more than 15 minutes, but the offense carries a small fine. Florida is not one of the 19 states where accidental cases that result in death carry criminal charges.

“It’s not a matter of punishing parents,” Duncan said. “It’s a matter of awareness and educating. You might think its only people who are careless, but it happens to very responsible parents.”