A major upgrade to the world's largest outdoor earthquake simulator reached a milestone mid-April when the facility's floor--all 300,000 lbs of it--was put back into place. When completed this fall, the simulator will have the ability to reproduce multi-dimensional earthquake motions with unprecedented accuracy to make structures and their residents safer during strong shakes. Researchers lay out the details of the upgrade in a paper published in January 2021 in Frontiers in Built Environment.