An image taken from video provided by Melanie Adaros shows sparks shooting from a cargo plane before making an emergency landing at Miami International Airport, January 18, 2024. (Photo: Melanie Adaros via AP)

The plane with five crew members safely returned and no injuries were reported.

The Federal Aviation Administration (FAA) and National Transportation Safety Board are investigating. The FAA said a post-flight inspection showed a softball-size hole above the engine, while the NTSB said it "has opened an investigation and is collecting information to evaluate and determine scope of the investigation."

Unverified videos on social media platform X showed flames shooting out of the left wing of the aircraft while in flight.

"The crew followed all standard procedures and safely returned to (Miami International)," the air freight company said, adding that it would conduct an inspection to find the cause.

US air safety expert John Cox said having problems with one engine is generally not a significant event, but the incident sounded like an uncontained engine failure due to the hole and NTSB investigation.

“On the interior of that engine there are a lot of rotating parts including blades," Cox said. "An engine is designed to try and contain a blade separation and they do testing and certification for it. But it does happen that you get an uncontained failure. When you do, it does elevate the investigative significance of it."

Investigators will be looking at questions like the age of the engine and its maintenance record.

Boeing said it is supporting Atlas and "the NTSB investigation into this incident."