[bennycog]

not really. they are well maintained and are held up with very strong material. a cave would probably collapse before man made ones. it also depends how deep you would go and where abouts the mine is. for example an underskilled mine site in africa would have a bigger chance of collapse.. most minesites that are run by big companies such as newcrest or bhp, have pretty high safety standards. this keeps the shareholders happy which is the only reason they have such high standards. so the materials and personnel they use will be of high quality. i wont say that they wont collapse but they surely have a better chance against others.