(Bloomberg News) Just as Hurricane Isaac threatened Florida last Sunday, a 2,500-pound ice sculpture appeared in downtown Tampa.

Carved to spell "Middle Class," the piece occupied Lykes Gaslight Square Park, a stone's throw from city hall and a police station. As seen in a video, about 1,000 revelers watched the 3-by-14-foot sculpture melt over 4 1/2 hours -- until "Middle Class" was entirely gone.

"It's a call to action," said Marshall Reese, an artist who created the work with longtime collaborator Nora Ligorano. "If no one does anything, the middle class will disappear just like the ice sculpture."

Ligorano/Reese, as the conceptual-art duo is known, planned to unveil the "Middle Class" sculptures on the opening days of the Republican and Democratic national conventions.

With the hurricane looming, their first event had to be rescheduled by one day.

"Thursday night we weren't sure we would be able to make it," said Reese yesterday in a telephone interview. "If the storm had tracked closer to Tampa we would never have been able to do it."

The duo has also melted ice sculptures spelling "Democracy" and "Economy."

Video Shot

The pieces are set in public spaces to engage an audience and record the process. The video shot in Tampa shows the letters melting drop by drop.

"For people to watch the middle class disappear in front of their very eyes, there's this aha moment," said Ligorano. "These artworks are monuments to what's happening to our country and our society."

Brooklyn-based Ligorano and Reese frequently tackle social and political issues in their art. Their 2004-05 "Line Up" series used images of members of the George W. Bush cabinet in mug shots as if it were a new form of portraiture.

They produced the "Pure Products USA" limited edition series in 2001 to mark the anniversary of the Supreme Court's decision to name Bush president. The group included a Bible Bar Energy Snack, Rumsfeld's Liberty Spread Peanut Butter and Homeland Security Nutrition Kit.

One of the items in the series was a snow globe with a bust of then U.S. Attorney General John Ashcroft. Its journey to Ashcroft's office was written up by the New Yorker.

Adventurous Collectors

The artists paid for their ice happenings, which cost between $10,000 and $15,000, with grants, a Kickstarter.com campaign and the support of private collectors.

"We are lucky to know collectors who are adventurous enough to sponsor something that disappears," Reese said.

Prices for their works range from less than $100 to $50,000. The next "Middle Class" melting is scheduled to take place on Sept. 4, in Marshall Park in Charlotte, North Carolina, starting at 11:30 a.m.

Muse highlights include Ryan Sutton on dining, Hephzibah Anderson on books.