THE SEAFRONT BLOCK of flats which collapsed near Miami had “major structural damage” to a concrete structural slab below its pool deck that needed to be extensively repaired, according to a 2018 engineering report on the building.

The report was among a series of documents released by the city of Surfside as rescuers continued to dig through the rubble of the building in an effort to find any of the 159 people who remain unaccounted for after its collapse.

At least four people were killed.

While the engineering report from the firm of Morabito Consultants did not warn of imminent danger from the damage, and it is unclear if any of the damage observed was responsible for the collapse, it did note the need for extensive and costly repairs to fix the systemic issues with the building.

It said the waterproofing under the pool deck had failed and had been improperly laid flat instead of sloped, preventing water from draining off.

“The failed waterproofing is 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,” the report said.

The firm recommended that the damaged slabs be replaced in what would be a major repair.

The report also uncovered “abundant cracking and spalling” of concrete columns, beams and walls in the parking garage.

It also noted that many of the building’s previous attempts to fix the columns and other damage were marred by poor workmanship and were failing.

Beneath the pool deck “where the slab had been epoxy-injected, new cracks were radiating from the originally repaired cracks”, the report said.

At the site where the building once stood, scores of rescuers used big machines, small buckets, drones, microphones and their own hands to pick through the mountain of debris that had been the 12-storey Champlain Towers South.

Today, a crane could be seen removing pieces of rubble from a more than 30ft pile at the site.

Meanwhile, firefighters were still dealing with smoke that continued smouldering underneath the rubble.

Miami-Dade mayor Daniella Levine Cava said that there was no change in the number of people still unaccounted for.

“We are at status quo,” she said. “I’m hopeful this will be a day that we will have a breakthrough.”

Rachel Spiegel was anxious for any update on her missing mother, 66-year-old Judy Spiegel, who lived on the sixth floor.

“I’m just praying for a miracle,” Spiegel said. “We’re heartbroken that she was even in the building.”