Mandalay Bay, the site of the Oct. 1 shooting, is not turning around as fast as expected, MGM Chief Executive Officer Jim Murren said Thursday. “This is a property that is undertaking a tremendous challenge” and it ”has lagged behind what we had predicted in terms of its performance,” Murren said. The property had a convention cancellation in February and several smaller meeting cancellations, Chief Operating Officer Corey Sanders said. While Mandalay Bay caters mainly to convention attendees some leisure tourists are also “electing to stay away” from the property, Sanders said.