NTSB official Todd Inman said "numerous" sources could have produced the sound, but it is too early in the investigation to offer further speculation.

The plane crash occurred Tuesday, shortly after takeoff from the Louisville Muhammad Ali International Airport in Kentucky. Investigators said the UPS cargo plane’s left wing caught fire and an engine fell off shortly after takeoff,

Thursday shows the aftermath of the deadly crash of a United Parcel Service (UPS) cargo plane. The Boeing MD-11 crashed shortly after takeoff from Muhammed Ali International Airport in Louisville, Kentucky,

The death toll climbed to at least 12 on Wednesday, Nov. 5, and several people remained unaccounted for, said Louisville Mayor Craig Greenberg.

The crash near the Louisville Muhammad Ali International Airport marked the deadliest accident in UPS Airlines history.

The Federal Aviation Administration (FAA) and the National Transportation Safety Board (NTSB) will lead the investigation into the incident.

A United Parcel Service (UPS) cargo plane crashed on the afternoon of Tuesday, November 5, at Louisville International Airport, prompting a shelter-in-place order across parts of the city.Footage posted on X by user @JedQuirimit shows a huge smoke plume billowing from the crash site in the distance.