"closed vertical blinds (thank goodness).....both went 'into' the blinds which went into the window. Fortunately the blinds covered the worst of the glass breakage and did most of the protecting from the glass at the same time"

Glad the kids survived. Note that they have made an important and historical discovery: vertical blinds are good for something.

Reminds me to put plexiglass in the back storm door. My kids are always racing through the house and slamming their hands on the glass to open the door; and I've actually seen someone else's child slice open his arm to the bone on another storm door, doing the same thing. Not the kind of lesson I want my kids learning experientially.