Study using satellite data had shown sinking land in Florida a year before the recent condo collapse

 

Shimon Wdowinski, a professor in the Department of Earth and Environment at Florida International University, analyzed datasets from the Interferometric Synthetic Aperture Radar (InSAR) to located where coastal flooding may cause the ground to sink. Results from the April 2020 study showed that the land where the Champlain Towers South condo was built in 1981, has been sinking at a rate of 1.9 mm per year (top circle on image) because it was built on reclaimed wetlands. Wdowinski said that this sinking rate alone would not cause the condo to collapse and pointed out that there are other areas that have a higher sinking rate per year (bottom circle). InSAR technology is also used to detect cracks in buildings which are an indicator that the building has moved in some way. That movement can go hand in hand with the sinking of the land beneath it, but in most cases there is not a tragic event that follows. 

https://www.dailymail.co.uk/news/article-9723841/Map-report-predicting-condo-collapse-reveals-Miami-Beach-spots-risk-collapse.html