Mystery of what caused South Florida condo collapse deepens

The collapse of a high-rise condo tower in South Florida early Thursday morning has left at least four people dead and 159 more currently unaccounted for. Now, as the search for survivors continues, a critical question looms: What caused the building to fall?

source https://www.cnn.com/2021/06/25/us/what-caused-surfside-building-collapse/index.html