Fearing that Columbine High School remains a target and an “inspiration” for potential gun violence, officials in Colorado have proposed razing the site of the massacre that left 15 people dead in what at the time was the deadliest school shooting in the nation’s history.

“School shooters refer to and study the Columbine shooting as a macabre source of inspiration and motivation,” Jason Glass, the superintendent of Jefferson County Public Schools, wrote Thursday in an open letter to Columbine students, parents and staff members and local residents.

The 20th anniversary of the attack, in April, was planned as a time for prayers and memorials, but instead hundreds of schools in Colorado were closed as the authorities frantically searched for Sol Pais, an armed 18-year-old woman who was infatuated with the massacre and who had traveled to the state from Florida.