Surfside Collapse Investigation Initial Findings

Authors

Lauren Millman, Vice President, Thornton Tomasetti

Liling Cao, Senior Principal, Thornton Tomasetti 

John Abruzzo, Managing Principal, Thornton Tomasetti 

Nicholas Saenz, Senior Principal, Thornton Tomasetti

Elisabeth Malsch, Managing Principal & Forensics Practice Co-Leader, Thornton Tomasetti

Publication

This article was presented at the ASCE Forensic Engineering 2024.

Abstract

Champlain Towers South collapsed on June 24, 2021, at approximately 1:22 am, killing 98 residents and injuring many more. The 12-story concrete residential building, built in 1981, housed 136 residential units. A review of the design and documents revealed that the patio and some of the building’s columns were too small. As a result, the reinforcement bars in the slabs did not provide enough continuity over the column tops, and the slabs were underdesigned for punching shear. The size of the columns and the reinforcement detailing, and placement explain the lack of robustness of the building that allowed the collapse to progress through most of the structure. At this time, the National Institute of Standards and Technology’s investigation continues, and until the material evidence analysis is completed, we will not be able to answer why the building collapsed when it did; however, there are lessons to be learned from the initial investigations.