‘Lockdown, lockdown’ is a kindergarten nursery rhyme at Massachusetts school

It’s not unusual for the walls of a kindergarten classroom to be plastered with colorful posters.But a poster in a Somerville, Mass., school caught the attention of Georgy Cohen and her husband, Rick Healey — and it didn’t have anything to do with ABCs or washing your hands.Handwritten in multicolored markers, the neat block print read:Lockdown, Lockdown, Lock the door<br>Shut the lights off, Say no more<br>Go behind the desk and hide<br>Wait until it’s