See what experts say is the probable sequence of collapse at the Florida condo tower

The cause of the deadly, middle-of-the-night collapse of a 12-story condominium near Miami Beach that left dozens buried in rubble is a mystery that could take months, if not years, of forensic investigation to solve. But while nothing is certain, there is a growing consensus among experts about the sequence of the collapse and the probable location of its trigger.

Six engineering experts interviewed by the Miami Herald on Saturday said that based on the publicly available evidence — including building plans, recent inspection reports, photos of debris, an eyewitness, and a surveillance video of the collapse — a structural column or concrete slab beneath the pool deck likely gave way first, causing the deck to collapse into the garage below, forming a crater beneath the bulky midsection of the tower, which then caved in on itself.

See the most probable collapse sequence, according to experts

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Appearing to reinforce the experts’ theory is the story of a resident who called her husband moments before the collapse to tell him she could see a crater in the pool area from the fourth-floor balcony of their ocean-front apartment. Then the line went dead, said Mike Stratton, who was out of town at the time. His wife, Cassie, is among the 156 people who are still unaccounted for.

Greg Batista, a professional engineer who specializes in concrete repair and worked on the Surfside condo’s pool deck in 2017, said that the way the building fell points to an initial collapse of the pool deck area into the parking garage, which then dragged down the other parts of the condo tower in a “domino effect.” Structural engineer and retired building inspector Gene Santiago agreed that was a probable trigger and pointed to a 2018 inspection, first reported by the Herald, that noted “major structural damage” below the pool deck.

Watch a surveillance video of the collapse

Miami Herald staff writers Linda Robertson, Jay Weaver, Taylor Dolven, Dana Cassidy and Aaron Leibowitz contributed to this report.

This has been updated to correct the number missing as of Saturday evening, June 26.

This story was originally published June 27, 2021 at 5:00 AM.