DALLAS -- An administrator from Dallas' Mi Escuelita Preschool was hospitalized for observation after opening a letter containing white powder Wednesday morning.
She reportedly put the letter in a zip lock bag and called 911 immediately.
No word yet on what the white powder actually was, but the discovery of it prompted an immediate evacuation of one building at the school's location in the 4200 block of Maple Avenue.
Ten staff members and a class full of children, ages three-years-old to five-years-old had to be evacuated.
The school’s executive director, Gayle Nave said the children are okay, but had to be sent home because they had no place else to house the children.
The Plano Hazardous Materials team responded to the 911 call just after 9 a.m. That is because the Dallas HAZMAT team is in training today.
The federal postal investigators arrived to take away the evidence.
On Tuesday, six schools and a church in five different north Texas cities, including Dallas, received threatening letters with white powder.
So far in those cases, the white powder has turned out to be a non life-threatening substance.
Nave told News 8 she was not even at her school when the staff member called 911. Nave said she was attending a head start meeting in which they were discussing what to do if a staff member discovers white powder.
Nave informed News 8 that her administrator never had a chance to see if there was a threat of any kind in the letter because the minute she spotted white powder, she put the mail in a plastic bag and called 911 as staffers have been instructed.