RAF VC10 quite a few years ago ended up on it's tail after three pallets with quite a hefty combined weight were loaded first and pushed right to the back. Believe the third pallet was fairly easy to push, going down hill as it was towards the end.
Can't provide dates, fairly sure it was at Brize Norton. May find it online or in old FS incidents.
Also check out the Accident Report for the C130 crash in Kosovo, believe 'loadshift' was a big contributory factor.