BEXAR COUNTY -- An Amber Alert was called off around 10:20 Thursday night after three children were found in northeast Bexar County.
The three siblings, two boys and a girl, were taken from Somerset Elementary School around 12:30 p.m. after a school nurse accidentally called the biological grandmother to pick one of the children up.
The children were in the custody of a Child Protective Services caregiver and the grandmother was not allowed to have contact with them.
The children had been removed from their mother's custody sometime after the school year began.
"This is definitely not the kind of situation that any of us want to be in," said Somerset ISD spokesperson Maury Vasquez.
"This points to the critical need for everybody -- caregivers, parents -- to make certain that students' emergency contact information is totally up to date."
The abducted children were 9-year-old Jose Olvera, 8-year-old Juan Garcia and 7-year-old Anna Liza Garcia.
According to Vasquez, the nurse called several other phone numbers before the grandmother finally answered.
She checked out all three siblings around 12:30 p.m. and left the school.
When the caregiver arrived at the school around 3 p.m., the school district quickly called Somerset ISD Police.
An officer who spoke with KENS 5 said he was concerned the grandmother had taken the children across the border at Piedras Negras, near Eagle Pass.
Four adults, including the grandmother, were detained by Bexar County sheriff's deputies after the kids were found safe in the 5600 block of Lakebend West.