A Massachusetts kindergarten class is drawing attention for using a lullaby to teach students about lockdown drills.
Taped to the classroom's chalkboard is a rhyme set to "Twinkle, Twinkle, Little Star," rewritten telling students what to do if there's a shooter.
It begins "Lockdown, lockdown, lock the door. Shut the lights off, say no more."
A mother visiting the Somerville school posted an image of the poster Wednesday to Twitter. It has been shared thousands of times.
Georgy Cohen, who took the photo, tells The Boston Globe it was "jarring." Online commenters say it's sad children have to be ready for a shooting.
The superintendent in Somerville came to the teacher's defense.
"As parents, as educators, we're trying to hold onto that innocence as long as we can, but the world keeps tearing it from us," Superintendent Mary Skipper told NBC10 Boston. "This is a teacher that, you know, was really trying in a very creative way to just help students reduce anxiety when they hear about or they fear a word."
Cohen and Somerville Public Schools declined to identify the school. The superintendent says lockdown drills are a sad necessity, adding that "unfortunately this is the world we live in."