Ingrid Hibbitts was supposed to be headed to Argentina for a wedding on Thursday evening when her American Airlines flight turned into something “like a nightmare,” catching fire after engine problems forced an emergency landing at Denver International Airport.

Days after an older Boeing 737 engine caught on fire, there's still few answers about what led to the sparks. But aviation experts are keyed in to reports of "engine vibrations."

An American Airlines flight from Colorado Springs to Dallas diverted to Denver after the FAA says the crew reported “engine vibrations.” Soon after landing, the engine caught on fire. In a harrowing scene,