Construction workers have begun removing the steel skeleton of the former Deutsche Bank building, a contaminated skyscraper next to Ground Zero. Challenges remain before it can come down for good, including an ambitious deconstruction schedule and an ongoing search for Sept. 11 victims' remains. This week several bone fragments were found on a floor searched months ago. The 40-story, 1.4-million-square-foot tower has part of the south tower collapsed into it, leaving toxic trade center dust and debris. Last week, a huge crane began removing steel beams and heavy equipment including heating units and elevator motors from the top of the building, said Bob Harvey, who oversees the project for the Lower Manhattan Construction Command Center. Workers are moving through the building's upper floors to remove toxic dust and other materials, and the city medical examiner's office is continuing a search for human remains. More than 760 bones have been found in the building since fall 2005. Black netting that has covered the tower has been cleared from the top floors and will continue to move down with the building. One of five buildings planned to replace the twin towers will be built on the site of the bank building.