This can happen quite easily on any cgo/combi aircraft especially if tailjack is not used or nose is not tied down and heavy pallets are being positioned on m/deck.
Not sure about MD11 but I think B747f have some safety device built in the inner hold system when aircraft senses tilt.
Some aircraft such as B747 combi are normally tail heavy due to the 7x M/deck pos at rear, not sure about MD11.