Enlarge / A logo on equipment stored near the OceanGate Inc. offices in Everett, Washington, US, on Thursday, June 22, 2023. (credit: Bloomberg via Getty Images)

The Ocean Sciences Building at the University of Washington in Seattle is a brightly modern, four-story structure, with large glass windows reflecting the bay across the street.

On the afternoon of July 7, 2016, it was being slowly locked down.

Red lights began flashing at the entrances as students and faculty filed out under overcast skies. Eventually, just a handful of people remained inside, preparing to unleash one of the most destructive forces in the natural world: the crushing weight of about 2½ miles of ocean water.