After just nine months in business, Volta has called it quits. Co-owner Umberto Gibin broke the news to Inside Scoop, saying Saturday was the restaurant's last day. Having just opened in December, this marks the fourth in a series of abrupt, high-profile closings in an obviously shifting dining scene, following on Bon Marché, Oro, and Cadence.

Also, to give you an idea of how precarious the restaurant business can be, Gibin tells the Scoop that the decision to close after an abrupt drop in business just last month. "We experienced a tremendous downtown in sales beginning in August," he says. "All of a sudden our sales dropped 30, 50 and then 70 percent." September didn't improve things, and rather than ask their partners for more cash, Gibin made the decision to close, saying, "I looked at our crystal ball and didn’t see it turning around."

The news is shocking only insofar as it's the second case where a positive review from the Chronicle's Michael Bauer — and in this case, being added to the Top 100 only five months ago — didn't boost business in any significant way. Bon Marché in the Twitter building was also well received for its food by Bauer, but closed in just under a year, in July.

The concept, which melded European brasserie food with Scandinavian items from chef Staffen Terje's personal background, perhaps was too much of a tough sell with so much competition for the expense-account set — including from the partners' other, longstanding hit, which is closer to the Financial District, Perbacco.

The space, behind Bloomingale's on Mission, with its glass-backed bar and impressive interior, must have required a hefty buildout having previously been home to 'wichcraft. The Westfield Centre will clearly be on the hunt quickly for a new operator/tenant.

In a post late Monday to Facebook, the team said, "Our hearts are heavy and our eyes are teary but we are so grateful to the loyal guests who have supported us along the way. We thought our unique concept and sleek design could counter some of the innate challenges of operating within the current San Francisco restaurant climate but the numbers tell us we were wrong."