Looks as though someone sat on it.

Unfortunately, there are certain catalogues featuring models doing just that.

Be it Rimowa or Halliburton, your alu case starts as thin mil sheet alu. The sheets are cut to size, and rolled through a hydraulic press with rolling dies that press the groves ( or Rillen ) into the alu sheet.

That stiffens the sheet alu up, which can be fashioned into a very light, strong, elegant case or attache, but by no means does it make the item indestructible.

One might imagine that the TSA and baggage handler's union would go out on permanent strike if a luggage case were introduced to travelers that was truly indestructible. It might certainly push work-stress related claims into previously unimagined, and astronomical numbers.