PG - happy to hear you are OK.
A colleague of mine was heading away with his family for a weekend visit to his outlaws. His wife turned the dishwasher on just before leaving, expecting to return home to clean dishes. When they returned the dishwasher had malfuntioned, buring out the dishwasher and spewing water. Water had been pouring out into the kitchen, through the floor and into a downstairs rumpus for the whole weekend. They had to renovate the kitchen which suspiciously had been a desire of the wife for some time.
We have a flat, Lakeside suburb in our City called Swansea. Most of the area is barely above mean sea level and can be flooded when king tides occur with high rainfall. The flat, low lying nature of the area presents problems for sewer servicing with surcharges a common problem (though a vacuum system is being progressively installed to overcome the problem). Cottages have yard sinks installed which allow sewage to surcharge into the yard if a blockage occurs. Unfortunately many home owners don't understand the prupose of these sinks and often modify or cover them when landscaping their properties. The outcome of that is, when they suffer a surcharge, the toilet will flood and they become the neighbourhood sewer outlet. If it is particularly bad, sewer can surcharge into laundries and kitchens. I don't personally know anyone this has happened to but have read plenty of letters from residents that want Council to fix the problem (we are not the sewer authority for our City by the way). The only upside is that those residents that receive a surcharge into their yards feel pretty fortunate.