Anything could have happened.
When the hot water tube gave way, anything could have happened.

If there was no one at home, the water would have flowed  non-stop from the overhead tank and no one in the entire apartment would have realised what was happening, for hours. If the heater switch were on and we were not at home, the coils would have overheated and possibly burnt a fuse somewhere as the water heated, boiled and flowed on, and no one would have known. If the tube had broken when one of us was taking bath, the boiling water from the water heater would have come crashing on us.

Instead, at eleven o’clock in the morning, long after the men of the house had left and I was working, the tube quietly slipped. I was alerted by the sound of running water and the whoosh of escaping steam. I rushed in to find the tube hanging and the bathroom filled with smoke, and I was able to switch the heater off in seconds. The security guard was within reach. The plumber was nearby. No damage had happened.  The matter was closed in ten or fifteen minutes.
Nothing had happened.