Iowa apartment building collapse raises questions about safety warnings and demolition plans.

Four days before the collapse of an Iowa apartment building, an engineering firm warned that it appeared at risk of crumbling. City officials did not order residents to vacate because they relied on the engineering team's assurances that the building was safe. Three people are still unaccounted for. The city released a cache of documents and permits showing a history of tenant complaints and issues plaguing the building. A citation was filed against the property owner for failing to maintain the building in a safe and sanitary condition.