This was an every day occurrence at the Safeway warehouse I worked at. We'd get heavy loads like that, stacked on cheap pine pallets like those, then the fucking computer system would slot them in top racks instead of a bottom rack. Over a period of time the pallet would give in to the weight and when the fork went to pull them, they'd just come apart. Pallets of cooking oil were loads of fun and the cleanup would take hours.
