New Flyer Industries Ltd. (New Flyer) is recalling certain model year 2014 NABI 42BRT transit buses manufactured from December 19, 2014, through June 6, 2015, and 2014-2015 NABI 40LFW transit buses manufactured from September 11, 2014, through June 3, 2015. The affected buses are powered with compressed natural gas (CNG) and are equipped with pressure relief devices (PRD) that may not function as designed, failing to vent a buildup of pressure, such as could occur if the CNG tank was exposed to fire.