Two Kelly Clarkson dates – including a July 10th performance at the Kiefer UNO Lakefront Arena in New Orleans and a July 12th show at Florida’s Pensacola Civic Center – were postponed.

Kiefer UNO also had to push back a July 11th on-sale for Jesse McCartney because concert-goers in New Orleans “weren’t thinking about going to a show,” GM Marco Perez told Pollstar.

Perez also feared the hurricane would damper a July 13th Duran Duran concert.

“Obviously, ticket sales did not come through this weekend,” he said. “With people in New Orleans not focusing on being entertained, they were in no mood to buy tickets over the weekend. So sales did drop, unfortunately.”

Pensacola Civic Center GM Cyndee Pennington told Pollstar the facility is holding three dates – two in August and one in September – to possibly reschedule the Clarkson show. Tickets originally purchased for the concert will be valid for the re-scheduled date, she added.

Hurricane Dennis also reportedly prompted the cancellations of a Tree63 concert scheduled after a Jacksonville Suns baseball game and a Tom Jones / Tower of Power gig at the Grand Casino in Biloxi, Miss. Both were scheduled for July 10th.

Dennis wreaked havoc on communities along the Gulf of Mexico, causing President Bush to declare parts of Florida, Alabama and Mississippi disaster areas.