A consultant warned there was evidence of “major structural damage” below the pool deck of a Miami Beach-area condo building nearly three years before it collapsed.
As officials continue to investigate what caused the deadly collapse at Champlain Towers South, officials in the Florida city’s Surfside suburb late Friday released a trove of documents related to the building, including the consultant's October 2018 report.
The findings from consultant engineer Frank Morabito also showed there was “abundant cracking” and crumbling in the underground parking garage of the 12-story building, which suddenly collapsed as residents slept in the early hours of Thursday morning.
Rescue operations underway in Florida condo collapseJune 24, 202101:21
Morabito said the waterproofing below the pool deck and entrance drive was failing, “causing major structural damage to the concrete structural slab below these areas.”
“Failure to replace the waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially,” he said.
The main issues with the waterproofing, Morabito said, were that it had been “laid on a flat structure,” which had not been sloped to drain, so the water sat on the waterproofing until it evaporated. This was a “major error” by the original developers, he said.
Why did Florida condo collapse?June 25, 202102:49
Morabito also noted that “several sizeable spalls were noted in both the topside of the entrance drive ramp” as well as the underside of the pool, the entrance drive and planter slabs “which included instances with exposed, deteriorating rebar.”
“Visual observations revealed that many of the previous garage concrete repairs are failing resulting in additional concrete cracking, spalling and leaching of calcium carbonate deposits,” he said, adding that he was “convinced that the previously installed epoxy injection repairs were ineffective in properly repairing the existing cracked and spalled concrete slabs.”
Morabito went on to recommend that concrete slabs, which were “showing distress” by the entrance and pool deck, “be removed and replaced in their entirety.”
“Unfortunately, all of these failed slab areas are under brick pavers, decorative stamped concrete and planters which require completed waterproofing replacement,” he said.
Morabito gave no indication that the building was in imminent danger, but he said that it needed repairs, which would be aimed at maintaining the building’s structural integrity.
“Though some of this damage is minor, most of the concrete deterioration needs to be repaired in a timely fashion,” he said.
Before his findings were made public by authorities in Surfside late Friday, officials said four people had been confirmed killed and 159 were still unaccounted for.
As search and rescue teams continued their round-the-clock hunt for survivors in the unstable mountain of debris, cranes and other heavy equipment were moved to the site of the disaster.
Teams also continued to tunnel into the site and dogs, sonar and cameras were deployed. Personnel from Mexico and Israel have arrived to help.
However, authorities had no insight Friday on what caused 55 of the 136 units in the Champlain Towers South's northeast corridor to collapse.
The National Institute of Standards and Technology said it was sending a team of six to the site of the collapse, according to Jennifer Huergo, a spokesperson for the federal agency.
After the team does its initial assessment, it will decide whether to do a complete investigation that would likely inform future building codes — the kind of work that was done after terrorists brought down the World Trade Center’s twin towers on Sept. 11, 2001, she said.
This article was originally published on NBCNews.com.