As members of The Church of Jesus Christ of Latter-day Saints, many of them from out of town, descend on Salt Lake City this weekend for the LDS Church's annual General Conference, they are certain to notice some commotion: Two blocks in the heart of downtown are kind of a mess.

The blocks that encompass the Crossroads Plaza and ZCMI Center malls are the site of a massive downtown renovation project, spearheaded by the LDS Church in its efforts to bolster the economy and tourism of its headquarters city.

ZCMI and Crossroads, both of which are owned by the LDS Church, will be torn down, as will most other buildings on the blocks, to make way for City Creek Center, a 20-acre mixed-use development, bringing new residential, retail and office space to the heart of downtown.

But with all the construction — or, more accurately at this point, deconstruction — going on, there will only be one wholly inaccessible area for conferencegoers to navigate. The sidewalk running along the east side of West Temple from South Temple to the Marriott Hotel is closed.

Other sidewalks are also closed, but they have been replaced by covered walkways.

When the center opens, which LDS Church officials expect will be sometime in mid-2011, it will include four residential towers on South Temple, office space both in existing and new buildings, three department stores — Nordstrom, Macy's and Dillard's — and two levels of smaller retail stores that front an indoor-outdoor pedestrian walk.

The retail component will be managed by mall giant Taubman Centers Inc.

There will also be a spot on 100 South for a 415-foot-tall fifth residential tower, which would be among the state's tallest buildings. It won't be part of the first phase of the development but will be built later depending on how quickly the other condominiums are bought up.

It will be built between the Marriott Hotel and the Crandall and McIntyre retail buildings, all of which will be spared by the wrecking ball. Other current buildings that will remain are the Gateway West, Eagle Gate, Beneficial Financial Group and Zions Bank towers, Utah Woolen Mills, the Qwest building and the historic Deseret/First Security Bank building.

Two more future condo buildings may one day be built on the block just east of the Crossroads block, and there will be two levels of apartments for rent above some of the retail space. In the end, there could be anywhere from 300 to 700 residential units in the project.

Church officials have not said how much they expect the entire development to cost, though city officials and others have estimated it could be an investment of $1 billion or more.