(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."