Crime Dad Pleads Guilty to Neglect After Children, 3 and 4, Climbed into Hot Truck and Died While He Slept The children's bodies were found in the back of their father's pickup truck on June 13, 2020 By Harriet Sokmensuer Published on July 14, 2021 12:49 PM Share Tweet Pin Email Teagan and Ryan Dennis. Photo: GoFundMe An Oklahoma father whose two children died in a hot pickup truck last summer admitted to falling asleep while he was supposed to be watching them. On Tuesday, Dustin Dennis pleaded guilty to two counts of child neglect in connection with the June 2020 deaths of his 4-year-old daughter Teagan and 3-year-old son Ryan, according to a release from the U.S. Attorney's Office in the Northern District of Oklahoma. "I failed my children," Dennis said in court Tuesday, the Tulsa World reports. "I didn't do what I was supposed to do, and because of that they died." Teagan and Ryan's bodies were discovered in the back of Dennis' pickup truck on June 13, 2020. At the time, Dennis told police he went to a local QuikTrip with his children around noon that day and then went home to take a nap. When he awoke, he said he found the children dead on the floorboards of his truck. State Charges Dropped Against Okla. Dad Whose 2 Kids Died in Hot Car — But Feds Might Prosecute As part of his plea agreement, Dennis admitted that while caring for his children, he got high on cocaine and stayed up to play video games. At one point, Dennis fell asleep, leaving his two children unsupervised. During that time, the children entered Dennis's vehicle in the driveway and got trapped inside, according to the U.S. Attorney's Office. They subsequently died of heat exposure. Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases. Tulsa County Jail Dad Released on Bond After Surveillance Video Shows His 2 Kids Climbed into Truck on Their Own Dennis was initially charged with two counts of second-degree murder, but weeks later, prosecutors said they had to dismiss state charges against Dennis because the children were Cherokee citizens and their deaths did not fall under state jurisdiction. In August, a federal grand jury indicted Dennis on two counts of child neglect in Indian Country. As part of a plea agreement, Dennis, 32, faces three to six years in federal prison followed by five years of supervision after his release.