Transcript for Authorities investigate cause of Florida condo collapse
other urgent questions. How does a 12-story condominium suddenly collapse? A building that withstood hurricane-force winds for years suddenly coming down. So far tonight, no evidence of a sink hole or a gas explosion. We do know of roof work that was being done, but authorities are not convinced that could have led to this. So, what was it? ABC's Stephanie Ramos on that part of the story tonight. Reporter: Tonight, along with the search for survivors, the other urgent question -- how would this happen? What led to this horrific collapse? It just doesn't happen. You don't see buildings falling down in America and here we had a building literally fall down. Reporter: The governor of Florida today saying getting to the bottom of what happened is going to take time. I know they're going to have engineers looking at this to try to identify what happened and what was the problematic occurrence. And so, that probably -- you're not going to have those answers immediately. Reporter: Tonight, experts are stunned by the magnitude of this collapse. No signs of sinkhole. No signs yet of a gas explosion. And they say buildings like these have backup structures to save the building if parts of it start to crumble -- and that did not happen here. They're built with redundancy so that one or two system failures would not cause a catastrophic failure like this. So more than likely again it's multiple things that have contributed to this. Reporter: According to miami-dade property records, the Champlain towers south was built in 1981. The 12-story building containing 136 units. Authorities saying 55 units, nearly half, were destroyed. This image showing the portion of the building that collapsed. The town of surfside commissioner saying the towers had been jute nice in recent years. It was up for its 40-year recertification, and that construction of an nearby building had led to some issues the building's garage. To my understanding there were some cracks from that project, minor cracks, but they were just patched up. Nothing, based on my understand, to the magnitude that would indicate there's a structural problem that would result in something so catastrophic. Reporter: According to the ap tonight, an inspector had been on-scene as recently as yesterday for that recertification process. And tonight, there are also questions about work that was being done on the building's roof. Though experts aren't convinced that could have caused something so catastrophic. There was roof work being done, but there's roof work being done on buildings all the time and it's hard to imagine that that could have been the impetus for such a catastrophic collapse, and I'm sure that it probably wasn't. Reporter: And investigators will likely look to something else, too. A 2020 study out of Florida international university. The school found that land in the Champlain powers area, had been sinking at an alarming rate during the 1990s. I was, like, shocked. We saw that the building moved 20, 30 years ago, which means whatever caused the collapse didn't start this year, it started many years ago. Stephanie Ramos with us. Steph, with so many questions about how this could happen, what is clear tonight that the families that survived this aren't going to be going back and they're being cared for nearby for now? Reporter: That's exactly right, David. The city is working to make sure those who are displaced have somewhere to sleep tonight. The mayor says many of them are staying at hotels behind me and at the reunification center which is just a block away from where we are, where you see the truck with the flashing lights. And the city is also working to get those folks their medication if they're in need, David. Stephanie Ramos on the scene in Florida for us, as well.
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