PHNOM PENH, Cambodia – Cambodia will build a memorial at the Tuol Sleng Genocide Museum to remember at least 12,000 people tortured and killed there during the radical Khmer Rouge regime, officials said Thursday.

The museum, formerly a high school in Cambodia’s capital, Phnom Penh, was turned into S-21 prison after the Khmer Rouge took power in 1975. Of the estimated 16,000 men, women and children who passed through its gates, only a handful survived.

The construction of the memorial will “ease the mind” of the survivors of the genocide and serve as an educational tool for the next generation to remember and prevent the return of such a dark regime, said Kranh Tony, an official attached to the special tribunal for the genocide crimes.

An estimated 1.7 million people died as a result of the Khmer Rouge’s radical policies from 1975 to 1979.

The Buddhist stupa will replace a similar memorial that disintegrated inside the Tuol Sleng complex. It will be completed in nine months.

The museum’s renovation began in 2010.