'Diarrhea all the way through the airplane': Flight turns back due to health incident. A Delta flight heading from Atlanta to Spain was forced to turn back after a passenger's diarrhea created a biohazard situation onboard.

In September 2023, a Delta Air Lines flight from Atlanta to Barcelona became a global news sensation due to a severe "biohazard" incident involving a passenger. Roughly two hours into the eight-hour journey over the Atlantic, a passenger experienced an uncontrollable medical issue that resulted in diarrhea being spread throughout the center aisle of the Airbus A350. The pilot made the executive decision to turn the plane back to Hartsfield-Jackson Atlanta International Airport, famously telling Air Traffic Control, "It's a biohazard issue... we've had a passenger who had diarrhea all the way through the airplane." Upon landing, the aircraft underwent an intensive deep-cleaning process that lasted several hours, which included replacing aisle carpeting. The flight eventually departed again with a new crew and the remaining passengers, arriving in Barcelona eight hours behind schedule, but the story remains one of the most cited examples of modern "travel nightmares" due to its visceral and unfortunate nature.