This is what I do for a living . Health & Safety Racking Inspections
Thankfully what happens in the video is NOT a regular occurrence in the UK, due to stringent safety checks something like the collapse in the video is very unlikely.
After going over the video and looking at the racking itself, myself and a number of other (fully qualified inspectors) have come to the conclusion the racking was not built correctly, possibly overloaded and a few other things as well.
Really feel for those that got trapped in that warehouse, don't know the exact circumstances but it didn't happen in the UK or Europe
www.cmdinspections.co.uk