Last October, construction workers were brought into Champlain Towers South to assess and repair worsening concrete damage in the building. But, according to documents obtained by USA Today, they discovered that the concrete deterioration had gotten so bad that workers couldn’t carry out repairs out of fear they would destabilize more areas of the condo complex. A summary of the work carried out on Oct. 13 reportedly said restoration and repair work “could not be performed” because it “could affect the stability of the remaining adjacent concrete constructions.” It’s still not known what caused last week’s collapse, which killed 18 people and has left 145 people still missing as of Friday morning. Meanwhile, officials are weighing up a plan to demolish the ruins of the complex after the search operation was paused Thursday over fears of a secondary building collapse.