For once, the vagaries of the River Lee were not to blame, but there had been a warning.
Met Eireann in Cork had told Cork Corporation that in a 12-hour period from 6 a.m. to 6 p.m. yesterday, it should expect the worst. The Met Eireann officials were spot on. They might have mentioned, though, that before dawn broke yesterday Cork would experience an incessant overnight deluge, the likes of which has not been seen for some time.
There was a brief lull in the early morning and then it started again. It came down in buckets and it didn't stop for most of the day.
Flooding in Cork - a city built on a marsh - is a regular occurrence when the prevailing winds and the high tides meet in a worst-scenario confluence. This time, the river held its banks but the gutters, designed to drain off surface water, couldn't cope.
There had been a dry spell, unusual for this summer, and grime as well as leaves signalling the beginning of the annual fall had begun to gather. When the rains came - and they came for a while in monsoon fashion - there was unprecedented clogging of what should have been the relieving arteries.
By mid-afternoon, when the local radio stations had done much to warn motorists of where the flash floods were, the corporation's switchboard was under some pressure.
But it wasn't the Lee. It was simply that there was too much water pressure underground, and manhole covers had started to blow. In the Mayfield area - on a height above the city, but with higher levels still above it - passersby witnessed an eight-foot gusher as a manhole cover was sent flying into the air.
Three inches of rain fell in a 12-hour period. In the height of it, the only positive development was that the Met people were predicting things would get easier as the evening wore on.
With local authority crews stretched to the limits trying to free the gutters, a corporation spokesman said he had rarely seen anything like it.
There were floods in the Douglas and Bishopstown suburbs, in Blackrock, Turner's Cross and Douglas Street, close to the city centre and in the city centre itself. In some premises, as the streets outside began to fill, the mops were brought out in an attempt to hold back the invading tide.
Traffic was forced to back up several times, but the general flow was maintained although at a reduced pace.
And then, as the rain eased off, the floods began to recede. By the time dusk had begun to gather, the water had almost but not completely subsided.
And yes, there were pockets of flooding in the county, too. But a spokesperson at Cork County Hall said there had been no serious disruption.