Davenport, Iowa – The collapse of a two-story apartment building in Davenport has left three people unaccounted for, according to officials. The disaster occurred on Thursday morning, four days after repair work had begun on the building, according to documents obtained by CNN.

The son of one of the missing persons has been sleeping at the site, hoping to hear his father’s voice. “I can’t just sit at home and wait for news. I need to be here,” he told Quad-City Times.

The Contractor who did repair work was also warned about the building’s precarious state four days before the collapse, according to The Independent. The contractor was reportedly warned that the building needed immediate attention to ensure that it did not collapse.

The mother-in-law of a woman trapped in the building collapse spoke to KGAN TV and revealed that her leg was amputated on the scene.

Rescue workers continue their search for the missing persons amid the rubble of the apartment building. The identity of the third missing person has not been revealed.