Delta has called the engine failure a "possible incident"

It is not something you'd want to see looking outside an airplane window thousands of feet in the air: a piece of metal rattling around like a roulette ball in the walls of a failed engine, set against a blur of spiraling bright orange.

That sight was captured amid panic and potential final goodbye texts among the 148 passengers a Delta flight from Atlanta to Baltimore on Monday, when the engine failure prompted an emergency landing in Raleigh, North Carolina.

Some passengers reported hearing a loud noise. Then things went south.

"After we heard the boom we just saw all this smoke come up into the cabin, and that's when we really started freaking out," passenger Avery Porch told Baltimore TV station WMAR. "It started slowing down a bit. It was getting hot. The air cut off."

Tyler Kreuger, Porch's boyfriend, sat next to her and contemplated a grim possibility.

"I pulled out my phone, and I know I didn't have service," Kreuger told WMAR. "I just texted my mom 'I love you', I texted my dad 'I love you.' "

In a statement, Delta Air Lines said Flight 1425 was diverted "after receiving an indication of an issue with one of the aircraft's engines."

An earlier statement from Delta called the failure a "possible incident." The company declined to say if passengers were in danger or describe what went wrong.

Media reports indicated Delta offered passengers $30 food vouchers as they waited for a flight out of Raleigh, and CNN reported the plane was back in service Wednesday after the engine was replaced.

The aircraft involved is an MD-88, the oldest aircraft in service by any airline, which is slated to retire next year, according to Bloomberg. Coined by pilots as "Mad Dog," the notoriously loud, cramped and antiquated planes are so reviled by pilots that Delta has offered to fast-track young pilots to the captain's chair if they agree to fly them, Bloomberg reported.

The age of the aircraft was not lost on passengers.

"Delta needs to retire those MD-80's, they are too old," Jose Bahamonde-Gonzalez told WMAR.

Porch had a positive view of Delta's response.

"I had a weird, eerie sense of calm over me, like I almost knew that they were going to take care of it, and they did," Porch said. "I don't think I'd be timid getting on a plane again being reassured that they handled it the way they did."

But Kreuger had a different takeaway.

"I can't get that bang and pop out of my head," he said of the loud noise. "It was very, very scary."