We ask all miners and managers to inspect any locations at their operation where chains are provided to protect persons from fall hazards. Identify and promptly correct the connection between the chain and the permanent termination point.
This alert contains a link to a short video that shows how easily a chain slides out of the hook when a horizontal force estimated at less than 20 lbs. is applied:
Recommendation due to file size:
Right-click on the link and choose "Save Target as" to save file locally, then play