Columbine High School, the site of one of America's most notorious school shootings, may be demolished because it remains a scene of "morbid fascination".

Two teenagers walked into the Colorado high school and shot dead 12 students and a teacher in April 1999.

But two decades on, local authorities have proposed tearing down and rebuilding the school because the building has remained "a source of inspiration" for people with a dark interest in the shooting

Jason Glass, the Jefferson County School District superintendent, wrote to parents saying people use Columbine as "a macabre source of inspiration".

Hundreds of people try to enter the school every year, with the number growing to "record levels" in the past 11 months as the 20th anniversary approached, he said.