The myth was based off Columbine High School massacre, in which teens Eric Harris and Dylan Klebold murdered 12 students, and one teacher, then themselves.
People talked about seeing two pedestrians which have similar skins to Eric and Dylan, shooting other pedestrians in Greenglass College. One pedestrian has been reported having a Tec-9 and a Sawn-off shotgun, the same weapons that Dylan used during the massacre. The peds have also been reported to yell the same words as Dylan and Eric did during the massacre, such as Do you believe in God? or Everybody with white hats stand up.
However, everything has been proven false, as no pedestrians with weapons can be found spawning in Greenglass College.