A spectacular plan for a vast glass complex of 700 housing units, shops, restaurants and art galleries along the Allegheny River on Fort Duquesne Boulevard has been suspended. We hope that doesn't mean scrapped.

The Pittsburgh Cultural Trust, which announced the $460 million RiverParc project two years ago, put it on hold last week, blaming the nation's credit and mortgage crisis. CEO Kevin McMahon said lead developer Concord Eastridge of Washington, D.C., never came up with an economically feasible plan and the collapse of the credit market compounded the problem.

The developer, in turn, blamed the trust, saying poor oversight and too much second-guessing had been the problem. That opinion was echoed by another developer who worked with the trust on a different project.

The claims and counterclaims go back and forth, but what stays the same is what a shame it would be if the city misses out on this beautiful, forward-looking development.

If constructed, RiverParc would have been Downtown's largest housing plan and one of the biggest in the world that's environmentally friendly. But it would have done more than increase the Golden Triangle's number of housing units. A grand boulevard would have bridged the riverfront and Penn Avenue with space for art venues, public parks and a valuable mix of housing options. Upmarket, for-sale condos and townhouses were contemplated along with the possibility of lower-priced rentals.

Even a model and architectural drawings for the project, which had been on display as part of an exhibit at the Carnegie Museum of Art's Heinz Architectural Center until Monday, seemed to be buzzing with activity. It was easy to imagine how this project would have enlivened Downtown.

The Cultural Trust, founded in 1984 to spur Pittsburgh's economic development through the arts, is responsible for the transformation of the Penn-Liberty corridor from seedy to vibrant. The organization has had clear long-term vision for the area. Although the trust was not successful the last time it attempted a large-scale project, a proposed-but-not-built 17-story office tower, it bounced back from that by completing accompanying plans for the O'Reilly Theater, Katz Plaza, an adjacent parking garage and the Wood Street Gallery.

Perhaps some or most of the RiverParc plan can be handed off to other players. Its promise was -- is -- that exciting. The trust, and the foundations that support its work, must find a way to recover from this setback, too.