This Denver condo tower won’t collapse, but its builder says a subcontractor’s moves led to cracks and risk

The Upton Residences is one of the tallest buildings under construction in Denver, bringing 461 condo units and two conjoined towers to a downtown corner.

But just as it nears completion at Welton and 18th streets, it’s grabbing attention for another reason: claims that a subcontractor’s behavior put the entire structure at risk.

The project’s developer, Amacon, claimed in court filings that a concrete subcontractor, GCon, removed a temporary support system from a floor of the project, leading to cracking. If the contractor had continued to remove materials, the lawsuit states, the “consequences of an unsupported structure may result in further cracks and potential collapse of the structure.”

But the builder is tempering those dire warnings. In a statement to local media, Amacon said th