In the early hours of June 24, 2021, part of a slab from a high-rise condo building in Surfside, Florida dropped into the parking garage below. Within minutes, the east wing of the 13-story tower collapsed, killing 98 people in a disaster without modern precedent in the US.

Designed in the late 1970s, the 136-unit Champlain Towers South was completed in 1981 and marketed as luxury living. Officials are still investigating why the tower fell. Engineers point to some key decisions during construction, that while legal at the time, compromised the buildings foundation and integrity.

For instance, a Wall Street Journal report concluded:

[The original builders] skipped waterproofing in areas where saltwater could seep into concrete, the available evidence indicates. They put the building’s structural slabs on thin columns without the support of beams in some places. They installed too few of the special heavy walls that help keep buildings from toppling, engineers say, features that could have limited the extent of the collapse. And they appeared to have put too little concrete over rebar in some places and not enough rebar in others, design plans and photos of the rubble indicate.

Tragically, the construction flaws could have been repaired. The report continued:

Engineers say some issues would have been fixable, had the property’s condo board done more extensive repairs sooner. By 1996, the slab started showing cracks, and pieces of concrete had fallen off the garage ceiling, unusual so soon after construction. Workers patched cracks and waterproofed the pool deck, but that too eventually failed.

But the condo board failed to act. Roof work began weeks before the collapse, but repairs to the steel-reinforced concrete hadn’t yet started.