Two teenage girls arrested Wednesday are accused of plotting "a mass casualty attack" at Memorial High School in Spring Branch ISD, according to authorities. The Spring Branch ISD police department was initially notified by the FBI of a potentially credible threat against the school on Tuesday and arrested the student involved,

The FBI arrested two teenage girls plotting a “mass casualty attack” using pipe bombs and guns targeting Memorial High School in Harris County, Texas, police said.

Two teenage girls were arrested on Tuesday, Feb. 18, after allegedly plotting a 'mass casualty' attack at Memorial High School in Houston involving guns and pipe bombs, according to reports.