50 years ago, on 4 April 1968, Dr. Martin Luther King Jr. – the leader of the civil rights movement in America – was shot dead in cold blood. On that day, Dr. King was in Memphis, Tennessee, to lead a demonstration and rally in support of a three-month-long fight for trade union recognition by 1,300 local refuse collectors.

A series of school walkouts in the United States has given voice to a range of social demands that go beyond the typical gun-control debate that has prevailed in Washington and the media. More than a million high school, middle school, and even elementary students on over 3,000 campuses across the US staged walkouts on 14 March—exactly one month after 17 students and staff were killed in the shooting at Marjory Stoneman Douglas High School. The Parkland, Florida shooting marks a tipping point, transforming the shock and grief of thousands of students into outrage and a vow to put an end to the horrific pattern of school massacres.