SURFSIDE, FLORIDA — Federal investigators determined the 2021 collapse of Champlain Towers South in Surfside, Florida, began weeks before the building fell. The National Institute of Standards and Technology issued a final report on Monday regarding the incident, which killed 98 people.

The agency reported that two connections between garage columns and the pool deck started to fail around early June 2021. The structure's original design did not meet building codes, and construction did not follow the design. Alterations made to the building over its 40 years meant other parts of the pool deck were not strong enough to withstand extra load.

Work done later around the pool, including the addition of heavy planters, sand, and pavers, further diminished the safety margins. Long-term degradation from corrosion also contributed to the reduced margins against failure. Photos taken by people at the building in the weeks before the collapse show a long crack in a planter wall on the pool deck and cracks where the planter wall met a planter box.

A person informed investigators that three weeks prior to the collapse, a part of a gate near the planter wall had dipped slightly, causing it to jam. Champlain Towers South collapsed into a pile of rubble at 1:22 a.m. on June 24, 2021.

Judith Mitrani-Reiser, an investigation co-lead, stated, "When building structures are designed and built to required codes and standards, they have margins against failure, meaning they should be able to support much more load than they are expected to bear." She added, "In the case of Champlain Towers South, these margins against failure were too narrow from the start."

A Miami judge approved a settlement of more than $1 billion for personal injury and wrongful death claims related to the collapse. Harley Tropin, who represented the families of victims and survivors in a class-action lawsuit, declined to comment on the new report. The companies responsible for designing and building the original structure in the late 1970s are no longer in operation. State legislators in 2022 enacted a law requiring condo associations to have sufficient reserves to cover major repairs.