Jackson was declared brain-dead after four days on life support.
"People automatically assume it happens to bad or neglectful parents," Bennett said.
She spent two years going over and over the mistakes she made and finally decided to go public as an advocate for swim safety in her community of Tomball, Texas.
Bennett thought she had taken the right precautions. She had two doors separating the house from the pool: a storm door over the back door and tight cover on the pet door. "We understood a doggy door was a risk for him to make it to the pool. We made it very clear that the dog door remains locked."
But that day was unusual. She had to pick her husband up from work after his truck broke down and grabbed her three kids. With no time to let the dogs out, she opened the dog door and left the house. "I was too impatient to wait for them."
When the family returned, she forgot it was open.
"There was a lapse in supervision. We thought he was safe upstairs with his sisters."
Drowning is highly preventable
The Bennetts' story is not unusual. Nearly 1,000 children died from drowning
in the United States in 2017. It's the leading cause of accidental death for children 1 through 4. More than 8,000 others nearly died by drowning, according to the American Academy of Pediatrics.
"Drowning is fast, silent, and can happen even when it is not swim time," said Dr. Benjamin Hoffman, chairman of the academy's Council on Injury, Violence and Poison Prevention, in a statement. "It happens to real families, families with good, attentive parents who never thought it could happen to them."
There are ways to keep it from happening to your child, according to the American Academy of Pediatrics and the Centers for Disease Control and Prevention. They call it the "many layers of protection to prevent drowning."
"Close, constant, attentive supervision" around water
Parents or caregivers should never -- not even for a moment -- leave young children alone or in the care of another child anywhere near pools, spas, wading pools or bathtubs, even if a lifeguard is present. Most young children who drowned in pools had been out of sight for five minutes or less and were in the care of one or both parents at the time, according to a study by the Consumer Product Safety Commission
The same goes for any standing water. Toddlers can drown in just an inch or two of water. Caregivers should also empty any water from containers, such as pails, buckets and kiddie pools, immediately after use. The rule is that an adult with swim skills should literally be within one arm's length, providing "constant touch supervision."
Bennett says this is where she failed. "You lose sight of your child. You think they're somewhere safe when they're really not, or you get distracted by a phone call at the pool."
The biggest danger is the lack of barriers to prevent access to the water
If you have a pool, you should completely enclose it with a 4-foot-high fence on all sides, separating it from the house and yard. The fence should have self-closing and self-latching gates. The American Academy of Pediatrics says such fences prevent more than half of swimming pool drownings of young children.
The academy is now urging states and local municipalities to pass laws requiring all pools to have these fences. In fact, 69% of children younger than 5 who drowned were not expected to be at or in the pool at the time, according to the Consumer Product Safety Commission.
Bennett says she wished she had put up a pool fence. "We could've done more."
Remove toys from pools after play
Bennett wonders whether her son was reaching for a toy in the pool and fell in. The group Water Safety USA
, a consortium of nonprofits and governmental agencies, recommends that all toys be removed from bodies of water when they're not being played with.
Parents, caregivers, older children and pool owners should learn CPR
Immediate resuscitation, even before the arrival of EMS personnel, "is the most effective means to improve outcomes in the event of a drowning incident," the American Academy of Pediatrics says.