Littleton became widely known in 1999 when the Columbine High School massacre occurred at Columbine High School , where two of the school 's students , Eric Harris and Dylan Klebold , murdered 12 students and one teacher , injured 24 others and then killed themselves . News media wrongly reported that the incident happened in the city , because the school 's ZIP code is primarily associated with Littleton . The school is actually located in adjacent Columbine , an unincorporated community , which is not a place name accepted by the U.S. Postal Service ; by default , locations in ZIP code 80123 use “ Littleton ” in their mailing addresses . Columbine High School is in the Jefferson County school system and is not one of the Littleton Public Schools
Columbine High School massacre
Columbine High School massacre
Littleton, Colorado