Original sentence: On May 15, 1974, it was the site of an attack by the Democratic Front for the Liberation of Palestine that resulted in the death of 21 people: see Ma'alot massacre
Edited sentence: On May 15, 1974, it was the site of a terrorist attack by the Democratic Front for the Liberation of Palestine that resulted in the massacre of 21 school children in an elementary school, by way of grenades and machine guns: see Ma'alot massacre