A group of girls were sitting together during lunch Monday at Seven Lakes Junior High in Katy, Texas.
Suddenly, they all began to look up from their phones at one another, stunned, then horrified, according to KTRK.
"It went from phone to phone to phone," 8th-grader Joy Smith told the station. "When everybody got it they started looking up at each other. I looked across the room and there was a table of black boys and they were looking at their phones, too."
Then, the same group of students received another threatening text from an unknown number, the Houston Chronicle reported. All the black 8th-grade students at Seven Lakes received them.
Now parents and school officials are wondering who could have pulled all their children's cell phone numbers. The school district's police department is now investigating who they came from.
The threats were sent just four days after 10 people were killed and 13 more were injured in the mass shooting at Santa Fe High School, just 60 miles southeast of Katy.
The exact language in the texts was not released, but KTRK reported that the two racially-charged texts contained the N-word and made threats of violence against the students who received them. Several parents rushed to the school to pick up their children
"The school administration along with the Katy ISD Police Department immediately launched an investigation to determine the source behind these inappropriate and offensive text messages," Katy ISD said in a statement obtained by Covering Katy. "As an added precaution, police presence has been increased and we will remain on high alert until the end of the school year."
According to the website, parents, students and staff members gathered before school Tuesday at the school's flagpole in a show of solidarity after the threats.