One of the most sobering points to have emerged from the Santa Fe shooting was that a number of students at the school had taken part in a walkout just 28 days prior to yesterday's shooting.
This photo was shared by City University of New York professor Angus Johnston who also runs the website Student Activism.
The walkout which took place on April 20 to coincide with the 19 anniversary of the Columbine massacre saw the group observe 17 minutes of silence and also read out a poem by one of the Parkland survivors.
The tragic image soon went viral and people offered their thoughts in response.
Santa Fe, Stoneman Douglas stands with you. ❤️ https://t.co/j0opfQwDKP