PPV fan blade explosion, lesson learned, looking for information.

I recently experienced a major failure of a PPV fan blade during a weekly check. We used to have a bag containing door chocks attached to the frame away from the fan housing. While at full throttle a strap from the bag came loose and was sucked into the fan. Immediatly the fan blades (composite) disintegrated with enough force to send large fragments through the metal houseing landing as far as 33' away.

Had I or anyone else been standing in the wrong place the incident could have resulted in injury or death.

Has anyone else had any similar failures of PPV fan blades? My department is concidering replacing our composite blades for wood. If anyone has information or experience with PPV blade failures I would like to hear about it.

Thanks and stay safe out there!