Plan to stage “mass casualty attack” at Houston-area high school thwarted, authorities say

Two teenagers are under arrest for allegedly plotting what the FBI is calling “a mass casualty attack” at a Houston-area high school.

CBS Houston affiliate KHOU-TV reports that Spring Branch Independent School District police say evidence suggests the suspects, both females, intended to place pipe bombs and shoot students at Memorial High School in the Houston suburb of Hedwig Village. There was no word on the motive.

The sheriff’s office in Montgomery County, just north of Houston, said it was “actively investigating a criminal case involving online threats made by two students.” One of them, the office said, is a student at Willis High School in that county and is in custody on unrelated charges. The second, the office added, is a student in the Spring Branch ISD and is being held in Harris County, which includes Houston.

Spring Branch ISD police told KHOU one of the teens is 16 years old and the other is 15. Their names weren’t released since both are juveniles.

The 16-year-old was charged with making a terroristic threat. The plan, shared through social media, was very detailed and that’s what led investigators to believe it was credible, police said.

It wasn’t known what charges the Willis High School student was facing.   

A letter KHOU reported was sent to Memorial High School students, families and staff said Spring Branch ISD police quickly arrested a student in the “potentially credible threat in the planning stages identified on social media.”

The sheriff’s office said it is “treating this matter with the utmost urgency and commitment, as threats of violence in our schools will not be tolerated.”

In response to the threats, officials have implemented additional security measures and are working closely with school administrators and law enforcement partners, the office added.