SPARKS, Nev. (AP) — A Nevada middle-schooler says a student who opened fire, injuring two classmates, aimed a gun at his chest before a teacher stepped in. The teacher was shot and killed.

Jose Cazares tells NBC's "Today" show that he initially thought the gunshots he heard Monday morning at Sparks Middle School were firecrackers.

But then he says he saw the boy shoot two students. He says he would've been next if teacher Michael Landsberry hadn't stepped in to try to stop the rampage.

Jose's mother called Landsberry a "true hero."

Authorities haven't provided a motive for the shooting. It's not known where the boy got the gun, which he used to kill himself.