Something you'd never see today

In the suppressed final episode, Walter Denton comes back to the cafeteria, wearing a black baseball cap, shades and a black trench coat. Angry at everyone making fun of his way of talking, Walter pulls a shotgun (not a double-barreled one but a semi-automatic one) and opens fire, killing everyone in the cafeteria until he blows his own head off.

In the final scene we see Connie and Conklin reading about it in the newspapers and congratulating theemlves on transferring to a different school before Denton lost it and went homicidal.