The incident took place at Schmid Elementary School in the 9700 block of South Greenwood.
Staff at the school exercised extreme caution this morning after a teacher who was fired Wednesday apparently made threatening remarks and police were called.
"They were out there and a few of the parents and concerned neighbors wondering what was going on at the school because no one could come and they wouldn't let any of the children out," said Stephanie Herrion.
Chicago Police say this morning officers immediately established a precautionary security strategy by monitoring the entrance doors of the building and checking the identifications of both visitors and occupants entering or leaving the school. All students are safe and the person who made the threat is in custody.
Roberta Anderson came to get her son when she couldn't get an answer from the school.
"There's no information. No phone call. I just had to come get him," she said.
Anderson said the former teacher had made inappropriate remarks to students and used racial slurs.
Anderson and her son, who had the teacher for math and science, say the fired teacher exhibited bizarre behavior.
"He used to act crazy? Yell out of the blue, just yell at people for no reason," said Jeremy Alexander.
As the day went on parents were alerted to situation.
"The last person you would think would do something or cause any harm to any child would be the teacher, so that was the main concern," said Alonzo Wilson. "I thought it might be a parent but a teacher, that's absurd."
The former teacher remains in custody at this hour, but has not been charged.
Despite the remarks made, the threat was contained.
But some parents would have liked to have had more information earlier in the day.