RIVERVIEW — Not expecting 4-year-old Logan Shepard to later wander outside the Riverview home he was visiting Saturday night, the boy's uncle let two pit bull terriers out of their cages to roam the yard. Moments later, they mauled the boy to death, Logan's father said Monday.The screams of Logan's mother, who discovered the gruesome scene, attracted the attention of deputies who happened to be nearby.Logan was declared dead. The incident remains under investigation but no charges have been announced, Hillsborough County Sheriff's Office spokeswoman Debbie Carter said. The dogs were later euthanized.Monday, family members shed more light on what they said led to the death and remembered a child for his independent spirit."He was so independent, he liked to do everything by himself," his father, Mike Shepard, said. "He even liked to toast his own bread in the morning."Stephanie Groulx, 43, had walked her son from their nearby home to his aunt and uncle's house at 12509 Rhodine Road in Riverview on Saturday night. The dogs' owner had caged the animals before the boy's visit, Shepard said.Once inside, Logan was given a bowl of ice cream and the adults went into another room to talk. The boy and his 15-year-old cousin remained in the family room watching television, according to his aunt, Delores Fredericks.A Sheriff's Office account released earlier said the boy had been left alone."This mother did not leave her child alone unattended, like they're saying," Delores Fredericks said Monday at Groulx's house. "We should've said, 'Logan, we'll be in the next room.' We should've said, 'Logan, don't go outside.' … We should've done all those things, but we didn't do it. That's our loss. We assumed everything."But the cousin did not realize that Logan had wandered away, Delores Fredericks said. And neither did the boy's uncle, Billy Fredericks Sr."Bill let his dogs back out to run the yard," Shepard said. "It's Bill's fault. He should've contained them dogs."Logan's grandmother, Norma Jean Bridges, said the family knew the dogs were vicious and she stayed away from the house because of it. "It was pure negligence, is what it was," Bridges said. "I never thought my little boy would be a statistic for dog bites."Fredericks later voluntarily surrendered the dogs to authorities. Monday, he declined to speak with reporters outside his house.Bridges, who lives next door, said her grandson enjoyed Curious George, mud-bogging, Power Rangers and cartoons. He was a smart boy, she said, who was always learning new things. His family said he loved seeing school buses drive by and couldn't wait to start preschool."He was funny, too," Bridges said. "When he wanted a banana, he'd make a sound like a monkey."Logan loved to play with their three family dogs — also pit bulls — Shepard said. He grew up with those dogs and never had problems with them, his father said.Shepard said Logan was around mud-bogging his whole life. The father and son would ride four-wheelers together or watch videos online. Even when he was only 2 or 3 months old in a car seat, his parents took him out mud-bogging."He was a lovable kid," Shepard said. "He loved mud-bogging. He'd get up and turn it on and watch it for hours."Contact Caitlin Johnston at [email protected] or (813) 661-2443. Follow @cljohnst.