SURFSIDE, Fla.—The oceanfront condominium building that 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 Saturday 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 …