Complex sentence: The building was abandonded after 9/11 and because it was too damaged by the WTC collapse and water from firefigters and sold to the Lower Manhattan Development Corporation for demolition and a memorial to be built at the site.
Split into simpler sentences: The building was abandonded after the September 11,2001 attacks because it was too damaged by the World Trade Center collapse and water from firefigters. It was sold to the Lower Manhattan Development Corporation for demolition and a memorial is be built at the site.