Saturday’s Pakistan International Airlines flight PK702 from Manchester, U.K. to Islamabad was delayed nearly 7 hours when a passenger wanted to go to the bathroom.
A woman seated towards the rear of the Boeing 777 thought the plane’s exit door was the lavatory. She opened the armed rear left door, deploying the emergency slide.
The aircraft had 393 passengers on board, 21 of which “had to be accommodated on other seats” and another 37 offloaded because “the airline was still allowed to operate the flight but had to reduce and reseat the passengers as the door wasn’t available anymore in case of a possible emergency evacuation.”
There has been a rash of similar incidents in China where there are a large number of first-time flyers. (It’s also common in China for passengers to create problems throwing coins into their plane’s engine for luck.)
For those unfamiliar you can generally use the lavatory when the seat belt sign is on provided you’re not on an active taxiway and provided the door you open actually is for the lavatory.