qnli question: On what date was it reported that the Las Vegas Outlaws were shutting down? sentence: On September 1, 2015, the Spokane Shock officially left the AFL and joined the IFL under the new name Spokane Empire, becoming the fifth active AFL/af2 franchise to leave for the IFL since bankruptcy (Iowa Barnstormers, Tri-Cities Fever, Green Bay Blizzard and Arkansas Twisters—now the Texas Revolution—left previously).