At least 12 people have died and more than a dozen are injured after a UPS cargo plane crashed while taking off from an airport in Louisville, Kentucky, on Tuesday evening.

Aviation experts who spoke to BBC Verify believe the plane crashed after one engine failed and another appeared to be damaged during take-off.

It is unclear what caused the plane to crash, prompting a massive fireball to erupt after it failed to take-off from the runway. Footage showed fire had already engulfed one wing of the aircraft while it was attempting to take off, which may have spread through the plane and caused the explosion, or the jet could have caught fire after colliding with an object on the ground.

The National Transportation Safety Board (NTSB) - which is investigating the crash - said they have recovered airport CCTV footage that shows the plane's left engine falling off from the wing during takeoff.

The agency has also recovered the cockpit flight recorder and the flight data recorder, known as the black box, from the wreckage, said the NTSB's Todd Inman.

What is also apparent is that the 38,000 gallons (144,000 litres) of fuel on board the MD-11 jet needed for the flight likely escalated the blaze, which quickly spread to several buildings beyond the runway and burned for hours.

BBC Verify has been analysing footage that emerged overnight to piece together how the crash unfolded.

How did it start?

UPS uses Louisville Muhammad Ali International Airport as a distribution hub for its global operations and its Flight 2976 was at the start of a 4,300 mile journey to Honolulu in Hawaii when the cargo plane attempted to take off.

Data from tracking website FlightRadar24 shows the plane began to taxi along the 17R runway at around 17:15 local time (22:15 GMT) and managed to reach a top speed of 214mph (344km/h).

But verified footage shows that by the time the plane reached this speed a fire had completely engulfed its left wing and the aircraft struggled to climb away from the runway before the explosion.

The NTSB said the plane's engine was on fire as it was working to take off and then detached from the wing. The plane was able to climb to 175 ft and cleared a fence at the end of the runway before veering into buildings and businesses surrounding the airport.

Officials issued a shelter-in-place order to local residents and scrambled hundreds of firefighters to the scene.

Governor Andy Beshear confirmed details seen in CCTV footage that shows the aircraft flying just metres off the ground before a bright flash engulfed the plane. It is then seen slamming into the ground as a huge fireball erupts around it about a minute into its journey.

What could have caused the crash?

Air traffic control communications reviewed by BBC Verify are largely garbled and full of interference so no meaningful conversation can be heard about the crash as it unfolded.

But analysts who spoke to BBC Verify suggested that a dramatic failure of two of the engines may have been responsible for the disaster.

The MD-11 transport plane uses three engines. Two are mounted under the wings, and a third is built into the tail at the base of the vertical stabilizer.

Footage confirmed by BBC Verify showed a blaze engulfing the left wing of the plane, which then tilted to the left as it attempted to gain lift and take-off.

Experts indicated that the left engine may have detached from the plane after suffering a mechanical or structural failure, and the NTSB later confirmed that the left engine detached during takeoff.

He referenced the 1979 American Airlines Flight 191 disaster, in which 273 people were killed after the plane's engine detached as it took off at O'Hare International Airport in Chicago. Parts of the engine had been damaged when it was replaced on the plane, but he said it was too early to say whether a similar fault caused the engine to detach on the MD-11.

The investigation remains ongoing, with questions about how the initial fire began and the impact of any debris on the third engine. The National Transportation Safety Board is leading the investigation, expected to take up to two years to complete.