A Swiss Airlines flight from Bucharest to Zurich was forced to make an emergency landing after the cabin filled with heavy smoke.
Twelve passengers were injured, while one crew member remains in intensive care after suffering serious injuries in the incident on Monday, according to reports.
Footage captured by passengers showed the cabin filled with thick smoke, that is believed to have been caused by engine problems.
The incident left the pilot having to make an emergency landing in Graz, Austria, The Sun reported.
Witness accounts suggested one of the engines exploded, sparking a fire and filling the cabin with smoke.
“There was a strange noise, a lot of smoke, and people couldn’t breathe,” a passenger told Austrian outlet Kleine Zeitung.
“I was sleeping when I woke up to the smell of smoke. I panicked and didn’t know what was happening.”
Another witness reported seeing an explosion and fire in the engine before the cabin was engulfed in smoke.
All 74 passengers and five crew members were evacuated from the aircraft.
Local police confirmed that 17 people required medical attention. A flight attendant was found unconscious during the evacuation and had to be resuscitated.
He was airlifted to a hospital in Graz, where he remains in intensive care.
An investigation into the cause of the engine failure and smoke is underway.
Swiss Airlines said: “Our thoughts are with those affected, and we firmly hope for our colleague’s recovery.”
Specialists are providing support to the hospitalised crew member’s family.
Graz airport was temporarily closed following the incident, causing delays and travel disruptions.
Swiss Airlines laid on a flight for Tuesday morning to return passengers to Zurich, ensuring they could reach their destination before Christmas.