400 chunks of concrete may explain what caused a deadly building collapse in Florida

MIAMI — A federal team investigating the collapse of a condominium tower in Surfside, Fla., has moved into the next phase of its work. Ninety-eight people died on June 24, 2021, when part of the Champlain Towers South building unexpectedly collapsed.

A team from the National Institute of Standards and Technology began its investigation days after the collapse, while search and rescue operations were still underway. Some of the debris from the site was later removed to a warehouse, where scientists and engineers with NIST conducted nondestructive testing.

Now the agency, part of the U.S. Department of Commerce, has moved some 400 large chunks of steel-reinforced concrete along with other evidence to a larger space. There, teams using heavy equipment can begin removing and testing concrete cores and samples of the rebar.

The NIST team is trying to understand why a portion of the 12-story building suddenly fell and to recommend changes to regulations and building codes to avoid similar disasters. Reporting by the Miami Herald and other news organizations has focused attention on possible construction defects that may have contributed to degradation of the building's concrete and its reinforcing steel.

NIST says the investigation of the Champlain Towers South collapse is "one of the most complex and challenging of its type ever undertaken, with no obvious initiating event for the collapse." The agency says its investigation won't be completed until spring of 2024. A report with recommendations is expected a year later.

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