What is the setting of Everlost by Neal Shusterman?

The majority of the action takes place in about a half dozen specific settings in and around New York City. Most notably is Mary's home in the Twin Towers. The Twin Towers no longer exist in the living world but do in Everlost. The building is different from how it appeared in the living world with some of the areas being remodeled by Mary to form suites of apartments, game rooms, and other rooms for the children. Some entire floors are virtually vacant. Another important setting is Leif's forest. The exact location is never outlined but it is noted the forest appears dead to the living but is a lush paradise to the dead.