A KLM flight from Amsterdam to Los Angeles had to turn around in the air, due to only one toilet remaining in use. The flight circled at an altitude of 10,000 km and landed back in Amsterdam 6 hours and 30 minutes after takeoff.
The plane did not return to service until the next day on a flight to Houston, USA. Commercial aircraft are required to have a certain number of toilets in good condition in relation to the number of passengers on board. Airplane toilets can be unusable for many reasons, such as being clogged by someone throwing up in the sink.