Crews on Monday morning started demolishing the remains of a six-story apartment building in Davenport, Iowa, that partially collapsed more than two weeks ago, killing three people and leaving dozens homeless.

Workers were using a large excavator to dismantle the 116-year-old brick, steel and concrete structure in a process officials said would take several weeks. It's a difficult task because the building is in the heart of the city's downtown and is believed to contain asbestos and other potentially hazardous material.

A section of the building fell away May 28, burying three residents in rubble at the base of the structure and forcing others to scramble out of the building. One woman was pinned under the debris and had to have a leg amputated to be pulled to safety.

IOWA WOMAN WHOSE LEG WAS AMPUTATED AFTER BEING INJURED IN DAVENPORT APARTMENT COLLAPSE FILES LAWSUIT

The city said in a news release Sunday night that officials have been discussing how to tear down the building with structural engineers, regulatory authorities and the company doing the work. As a precaution, the city ordered that residents of nearby apartments vacate their homes during the demolition.

Since the collapse, officials have faced repeated questions about why tenants were allowed to stay in the building despite warnings that it had serious structural problems.

The day before the collapse, firefighters were called to the building because of concerns about an unstable wall. On Sunday, the city said in a news release that fire crews went to the building and saw work was being done and that there appeared to be shoring of the structure in place.

The release adds that a city building inspector also visited the site that day and "determined that the work appeared to be progressing in accordance with the plans and specifications previously submitted by a professional engineer." The city said there were "no observable signs of difficulty or bowing in the external shoring."