A SWISS International Air Lines Flight LX9 was diverted after it declared an emergency while isolated over the open sea in the Atlantic. The transatlantic flight, operated by a Boeing 777-300ER, took off from Chicago O'Hare International Airport on Monday for an eight-hour-and-45-minute flight to Zurich Airport in Switzerland.

However, about four and a half hours into the flight while the plane was at 37,000 feet, the crew transmitted a squawk code 7700 to declare a general onboard emergency. Flight tracking data shows the aircraft was flying over the Atlantic when the emergency was declared, prompting it to take a right turn and divert from its North Atlantic track.

It landed safely on Runway 33 at Lajes Air Base (TER), a joint civilian-military facility that acts as a primary diversion airport for transatlantic wide-body operations on Terceira Island, on Tuesday morning after roughly six hours in the air. SWISS International Air Lines stated that the crew detected an unidentified pungent odor in the economy class cabin, prompting the precautionary diversion.

The carrier added, "Approximately five passengers and one crew member underwent precautionary medical examinations after landing, having briefly experienced symptoms such as irritated eyes, nausea, or headaches." Ground crew is currently examining the plane, and the aircraft is scheduled to resume its journey to Zurich, pending final clearance, on Tuesday afternoon.