A Pakistan International Airlines flight waiting to take off from London to Islamabad was delayed for seven hours after a passenger opened the emergency exit door thinking it was the bathroom.
The passenger somehow missed the very clear emergency exit signs on the door and unlocked it, setting off an alarm and deploying the emergency slide. Passengers had to be taken off the plane. They eventually re-boarded and took off, but only after having to wait for nearly seven hours.
The airline tweeted a reminder to travelers to "follow security instructions as such mishaps result in inconvenience of hundreds of other passengers."