Church leaders are highlighting a massive seismic upgrade beneath the Salt Lake Temple as one of the most significant but least visible accomplishments of the ongoing renovation, according to KSL.

The project involves isolating the historic temple's foundation on giant base isolators designed to let the building move independently during an earthquake, protecting both the 19th-century granite structure and its underground additions. Engineers estimate the upgrade could allow the temple to survive a major Wasatch Front earthquake that would damage or destroy most older buildings in downtown Salt Lake City.

The base isolation system sits beneath the temple and its four-story underground addition, representing years of engineering work that will remain entirely hidden once the renovation concludes. The temple's exterior renovation and landscaping work is nearing completion, with public visibility increasing after years of construction barriers.