Two autistic Long Island children were able to stroll off their schools' grounds unnoticed fewer than 48 hours apart last week -- and one of them ended up killed while walking along a busy highway.
The terrifying back-to-back security lapses now have Nassau County parents furious and officials scrambling for answers on how the pair of vulnerable kids could have slipped away from supposedly secure campuses in broad daylight.
"Our world was shattered," Danecia Lewis, a grieving sibling of killed 15-year-old Christopher Williams, wrote on the family's GoFundMe page.
"Instead of ensuring his safety, the school called my mom asking where he was -- unaware that he was already gone -- a short time later, a detective called her to identify his body," Lewis said.
Christopher, a student at the Martin de Porres School for Exceptional Children -- a school for kids with special needs -- slipped away from the campus unnoticed Thursday around 1 p.m., officials said.
Minutes later, he was fatally struck while walking along the Southern State Parkway near Exit 13 in Valley Stream and was rushed to Long Island Jewish Hospital, where he was pronounced dead.
Joe Trainor, the school's executive director, told The Post that the community is "heartbroken" by the loss.
"We extend our deepest condolences to the student's family, friends, and loved ones," Trainor said, pledging to complete a top-down review of the school's policies to determine what went wrong.
But Williams' family doesn't believe condolences from school officials are enough and are calling for accountability in the teen's death.
"He was only 15 years old, with his whole life ahead of him," Lewis said. "The school failed him, and now our family is left grieving an unimaginable loss."
Only one day before the tragedy, another autistic student, just 5 years old, slipped away from the playground at Riverside Elementary School in Rockville Centre during recess, scaled a fence and walked a half mile home alone.
The child's parents, who did not release their names, revealed to local outlet News 12 Long Island that they came home to the shocking surprise of their toddler already inside the house waiting for them.
The school had called the police as soon as it realized the child was missing, although it's unclear when that was, and cops arrived at the family's home roughly 10 minutes after the call was made, according to school officials and police.
"The district takes student safety very seriously. We are aware of the incident and are actively investigating," the Rockville Centre School District said in a statement.