Like the rest of the world, we watched in horror as the news unfolded about the building collapse in Surfside and wondered “How could this happen?” Since this is raising many questions for building owners, we want to share a summary of what we know and what owners can do for peace of mind.
What we know so far
It’s too soon to know what caused the collapse, and the facts are unfolding each day. Speculation has ranged from delayed repair of structural problems identified in a report completed in 2018 to subsidence of soils in the area and even vibrations from on-site and nearby construction. Here is a brief summary of what have been reported as the possible contributing factors:
- The review of video suggests that the cascading collapse began in the area of a swimming pool located at the ground floor before spreading to the central portion of the building, and north and east facing building elevations.
- An engineering report completed in 2018 indicated structural concerns at the property as well as damages to finishes (columns, walls, ceilings, floors) that could indicate bigger issues, but it is not clear whether those conditions contributed to the collapse of the structure. It has been reported that the condo association had recently imposed a $15 million assessment to fund some unknown level of repair.
- Subsidence (settlement or migratory movement) of soils in the area are also cited as a possible contributing factor. South Florida has unique geotechnical challenges including shallow groundwater, loose soils, and irregular rock layers that are composed of soluble carbonate. These factors make buildings in that area prone to subsidence. It is likely that the building is founded on deep concrete piers; however, subsidence could result in a shift in the equilibrium of forces imposing secondary load effects to be managed by the building structure.
- Although Florida in general is known for sinkholes, and this site is located in an area with carbonate bedrock, sinkhole activity is relatively uncommon in this part of the state.
- Others have speculated that vibratory ground movement from nearby construction or recent rooftop construction at the property may have been a contributing factor.
Building owners are asking “Should I be worried?”
We have been fielding calls from many worried building owners asking what, if anything, they should be proactively doing right now. While the collapse is so very tragic and has many clamoring for a clear answer, it is possible that this event resulted from a combination of factors which may be unique to this property. Currently, there is no reason to believe that other structures in the area are at risk; however, county officials have ordered an audit of buildings that have not completed the recertification process (40+ years old, 5+ stories tall). This county audit does not apply to cities; they are being asked to do their own audit of properties.
As a general principle, we suggest taking a cautionary approach, in that any structural or site stability concern identified, observed, or reported at a property, should be carefully considered. Many times, building structures give us warning of maintenance needs, such as a leaky roof, cracked window glazing, cracking in the masonry, settlement of interior grade-supported slabs, or cracked and spalling concrete. This is just a short list of what may be observed. Sometimes, these observations may be unrelated to building structure performance; however, any of these observations could be our building structure communicating something of significance to us.
While building collapses like this are exceptionally rare, it may provide some peace of mind to revisit older multi-story buildings in your portfolio, especially if you have had any prior reports (property condition reports, structural or geotechnical evaluations, or concerns from occupants or maintenance personnel) that identified potential concerns with the structure or site stability. Here’s what you can do:
- Look for areas where your building has or is communicating something to you, such as those examples noted above
- Assure that any known issues have been researched and addressed in some constructive way
- Engage an engineer to evaluate the property if needed for peace of mind
It could be months or years before we know the specific cause, and as the facts unfold we may glean lessons about what to do differently to prevent a future tragedy like this. There has already been some discussion of changing inspection requirements or frequency, but we can’t predict what changes will happen. For now, we will continue to hold out hope that more people are alive and can be rescued as frontline public safety workers pick through the debris. Our thoughts are with the families and the entire community in this incredibly difficult time.