Afterward, Salt Lake Chamber President Lane Beattie took some swipes of his own - at the mayor. Beattie contacted The Salt Lake Tribune to say he was disappointed that Anderson threw "hand grenades" at the church.

Beattie said the mayor should have focused on what the city could do on its own, such as facilitating downtown housing.

"What an incredible time to have a leader to stand up and say, 'This is what we're going to do,' " Beattie said. Instead, "all it was was, 'We need to know more from the LDS Church.' To continue to castigate the fact they're doing their professional jobs is not helpful but continues to drive wedges. It's time for us to build and to be positive and proactive."

Thirteen groups sponsored Tuesday's forum, called "The Vibrant Downtown," including the chamber's partner, the Downtown Alliance. The panel included four national speakers with experience in urban redevelopment.

All agreed that exciting downtowns offer a blend of high-density housing, distinct districts and unique uses, including retail, to draw suburbanites.

And they say Salt Lake City has the ingredients for success, with its light-rail system, its neighborhoods that feed residents onto Main Street and its new emphasis on education, with the Brigham Young University Salt Lake Center and LDS Business College opening at the Triad Center and Salt Lake Community College returning to Main Street.

"Salt Lake is at a crossroads," said Daniel Rosenfeld, a principal in Urban Partners, a Los Angeles-based real estate firm. "You can either go one of two directions" - toward Portland, Ore., considered a model of urban development, or L.A., a city choked with freeways and lacking a 24-7 downtown.

The formal discussion mostly steered clear of the LDS Church's plans for Crossroads Plaza and ZCMI Center malls - the largest component of downtown's redevelopment. The church has announced the combined malls will be anchored by Nordstrom and up to two more department stores - Meier & Frank says it is staying, and the church's developers are talking with existing anchors Mervyn's and Borders. They will also include up to 900 housing units.

Ron Pastore, a Boston-based retail expert and the church's redevelopment consultant, was on the panel and spoke generally about the project, saying it will connect to the surrounding blocks.

As an example, he pointed to Copley Place in Boston's Back Bay. He said the design will incorporate views of the environment.

"Here is a place of unusual natural beauty. Why in the world would you go back and put a box there? You want to make sure it's as open as possible."

But the centers will be enclosed. And while Pastore praised 24-7 downtowns, Anderson fears the city is headed toward a 10-hours-a-day, six-days-a-week downtown. The church hasn't said whether the malls will be open Sunday.

Anderson ticked off a list of cities where indoor downtown malls haven't worked. "Enclosed malls trying to segregate people are not what we're seeing in urban areas now."

At least one speaker agreed.

Alex Marshall, a journalist and author of How Cities Work: Suburbs, Sprawl and the Roads Not Taken, told how the mall in downtown Norfolk, Va., spurred surrounding development but another in downtown Columbus, Ohio, was a bust and is now listed on the Web site www.deadmalls.com. Both were developed by Taubman Centers Inc., the same company hired by the LDS Church to make over Salt Lake City's shopping centers.

Malls are "not the highest and best use. Downtowns should be about public places. A mall is about private spaces," Marshall said. "That isn't to say they should always be rejected."

Anderson would like the church to seek public input as it designs the malls. He said he is "duty-bound" to seek more information on such an important project to help ensure it succeeds.

"We're still hearing, 'We got to keep it close to the vest.' We've been hearing that for how many months now?" Anderson asked the crowd.

Unless they receive public money or desire zoning changes, developers don't generally ask for public comment. In this case, the church may pursue a zoning change to build a sky bridge over Main Street to connect Crossroads and ZCMI, something the mayor opposes.

Bruce Bingham defended the LDS Church's silence and likened it to how he is developing a $100 million-plus office tower near 200 South and Main.

"We want to get it right before we unveil it," he told the forum. "Quite frankly, it's my money."

After the panel discussion, Pastore said Anderson's concerns about design are valid. "They're not falling on deaf ears," he said, adding that the plans remain under wraps because the mall redevelopment is complex.

Beattie complained the mayor's criticisms were premature. "We ought to wait until we see what the plans are from Taubman and the church and then respond to it."

By then, Anderson worries, the design will be a done deal.

hmay@sltrib.com