The restoration project of the Edicule in the Church of the Holy Sepulcher in Jerusalem has recently been completed, but scientists warn that the church may still suffer ‘catastrophic’ collapse.

According to National Geographic, scientists at the National Technical University of Athens said some portions of the shrine’s foundation actually sit on rubble of earlier buildings, and unexplained tunnels and voids. The foundation mortar of the structure has also crumbled due to long term exposure to moisture. The discovery was made with ground-penetrating radar and robotic cameras.

“When it fails, the failure will not be a slow process, but catastrophic,” Antonia Moropoulou, NTUA’s chief scientific supervisor told the National Geographic.

To address this risk, scientists at the National Technical University of Athens are proposing a 10-month project that would cost $6 million euros which would involve removing the fractured foundation and installing drainage system around the perimeter of the rotunda.