The Indiana Gaming Commission is conducting an investigation of Columbia Sussex Corp. regarding statements it allegedly made about staffing levels at its newly acquired Casino Aztar riverboat. Columbia Sussex became the owner of the boat, based on the Ohio River at Evansville, Ind., when it acquired casino operator Aztar Corp. in January. Ernie Yelton, executive director of the Indiana Gaming Commission, confirmed that a probe has been launched at the request of the mayor of Evansville.