A safety film detailing the various grisly ways heavy machinery can mangle human flesh if you are not careful and the guys in this film certainly arn't. One of the guys is shown changing the wheel on a large excavator and ends up demolishing a house!
What makes the film unintentionally hilarious is the gritty country & western soundtrack. As the song says, being distracted or hungover might cause you to fall from a JCV or have your hand cut to pieces in a grinder. So lay off the Jack Daniels and pay attention!