(CNN) -- A woman who was babysitting a 5-year-old who fatally shot himself Monday with her gun has been charged with abandoning or endangering a child, a felony, and jailed in Orange County, Texas, police said Wednesday.
Bail was set at $250,000 for Melissa Ann Ringhardt, 19, said Clint Hodgkinson, chief deputy with the Orange County Sheriff's Office.
The death was "avoidable," according to Hodgkinson, who said Ringhardt failed to secure the gun while she was caring for the boy, John Allen Read, and a 6-month-old, both children of Kayla and Joe Read.
Ringhardt was a regular babysitter for the family, with whom she had been living in Vidor, Texas, for the past few months, police said in a statement. Vidor is 95 miles east of Houston.
"Ringhardt stated to investigators that she was carrying a handgun on her person in the home that day because she was scared being at home alone," the statement said. "The handgun was a semi-automatic .40 caliber pistol. Ringhardt left the handgun on a coffee table in the living room and went to the bedroom to take a nap. When she was awakened from her nap, she noticed she didn't see John around the house. She began looking until she found him deceased in the living room with the fatal gunshot wound."
The infant was not hurt.
Hodgkinson said the elder child sustained a gunshot wound to the head and is believed to have died instantly.
With no phone at the house, Ringhardt carried the boy's body to his grandparent's house nearby, and police were called.
At the time of the shooting, the child's mother was at a hospital with another of her children, and the father was out of town on business. The father, Joe Read, said his neighborhood was not unsafe. He would not comment further.
"The preliminary investigation appears to be that the shooting was accidental," police said in a statement.
This is at least the fourth instance since June of a child dying from a self-inflicted gunshot wound.
Last weekend, a 2-year-old girl fatally shot herself in Fayetteville, North Carolina, and the toddler's father faces involuntary manslaughter charges, police said.
In New Orleans, a 5-year-old girl died June 23 after she came "into contact with a .38-caliber revolver and accidentally shot herself in the head" while her mother was at a store, police said.
The girl's mother was charged with cruelty to a juvenile until the 5-year-old died, at which point prosecutors added a second-degree murder charge. A judge in the case threw out the murder indictment last month, and the district attorney's office said it would appeal the decision, CNN affiliate WDSU reported.
In August, a 3-year-old boy in Dundee, Michigan, found a .40-caliber handgun belonging to a family friend on a closet floor in his home. He died after accidentally shooting himself in the head, police said. The family friend was charged with careless discharge of a weapon, a misdemeanor.
Two weeks ago, 2-year-old Michael Garcia Jr. was taken to a hospital after shooting himself in the legs with a .45-caliber handgun registered to his mother, according to CNN affiliate WFTV. The boy's wounds were not life-threatening, and the boy's father was charged with child neglect, the station reported.
According to the Centers for Disease Control's National Center for Injury Prevention and Control, 703 children under the age of 15 died in accidental firearms deaths between 2001 and 2010, the latest year for which data are available.
During the same period, 7,766 children under the age of 14 suffered accidental firearm injuries.
CNN's Eliott C. McLaughlin, Marlena Baldacci and Brian Carberry contributed to this report