Nobody likes bad news. If something is out of order, has turned for the worse or just doesn't go as planned, we are normally not too fond of hearing about it. Breaking bad news is thus a highly sensitive social activity that may easily involve casualties on the part of the deliverer, a phenomenon known as "shooting the messenger." To avoid such bloodshed, the Japanese language offers a number of words and expressions that help convey bad news in a maximally innocuous way.
The domain where this can most easily be studied is public spaces — for instance, when there is a cash dispenser out of order, a broken toilet or an electric signboard that doesn't work. To be sure, Japan can take some pride in the fact that unlike in many other countries, these things usually work amazingly well. But in those rare cases they don't, this makes it even harder to appropriately announce such circumstances.
The most straightforward way to acknowledge dysfunction in the public arena would be the term 故障 (koshō, out of order). However, being straightforward is perhaps not what is most required here — which is why the expression is often avoided. A more favorable way to announce that something is broken is to call it 利用中止 (riyō chūshi) or 使用中止 (shiyō chūshi), "usage suspended." I could never quite figure out the difference between the two, but the point for both is that they go without any acknowledgement of defect or brokenness. In addition, "suspended" conveys some minimal degree of hope that the apparatus in question won't remain that way forever but will be fixed in due time.