First, welcome to OCC....
The Plastic Fans are fairly durable. My guess it hit something to explode.
(A) Make sure the fan is secured to the Drive Shaft with the mounting bolt.
(B) If you have excessive "wobble" in the Drive Shaft, check (1) the Flex Disc on each end of the drive shaft, and (2) check the Pilot Bushings in the Flex Disc Couplers.
If any parts are worn, replace as necessary.
