More than 30 million viewers in Britain tuned in to watch the BBC “Royal Family” documentary in 1969, such that during the intermission, the flushing of toilets all over London caused a water shortage.
Proof of viewers

More than 30 million viewers in Britain tuned in to watch the BBC “Royal Family” documentary in 1969, such that during the intermission, the flushing of toilets all over London caused a water shortage.