Investigators searching for what caused Tuesday’s deadly UPS plane crash in Louisville, Kentucky, will be reviewing dramatic video footage from the scene in addition to the crucial voice and data recorders, generally known as black boxes, which were recovered Wednesday.  

The footage appears to show the area of the left wing where one of the plane’s engines would be located on fire as the McDonnell Douglas MD-11 raced down the runway toward disaster. Officials said at least 12 people were killed in the crash, and the death toll was expected to rise.

Moments later, as the plane with three crew members on board seems to try to take off, some flames appear to shoot from the engine located in the tail of the plane.

Todd Inman, a member of the National Transportation Safety Board, confirmed to reporters Wednesday that airport security camera footage shows the plane’s left engine detaching from the wing during takeoff. Earlier, still images and aerial video footage had appeared to show the engine sitting just off the runway. It is possible that debris from the separation was sucked into the tail engine.

Federal authorities investigating the crash are expected to prioritize securing the left engine as well as locating the cockpit voice and data recorders from the wreckage as they work to determine what caused the catastrophe. 

With one engine gone and a second engine potentially either damaged or not functioning properly, it is unlikely the plane — loaded down with fuel and packages — could generate sufficient lift to take off.

The MD-11 was designed to be able to take off without one engine, but losing two engines while approaching 200 mph and running out of runway to stop would have given the pilots a seemingly impossible situation to try to work through.

Also, having an engine fall off the plane would alter the weight and balance of the aircraft, likely making it harder to maintain stable flight — assuming the wing itself wasn’t damaged during the fire and apparent engine separation.

The plane would have been carrying up to 20,000 packages and roughly 255,000 pounds of jet fuel for its flight of eight and a half hours to Honolulu. 

The black boxes are located in the tail section of the MD-11 because typically that’s the most survivable section in a crash. They will be secured and rushed back to the NTSB lab in Washington, D.C., for examination. Inman said Wednesday that the voice and data recorders “suffered some heat, not intrusion, but heat around it” and noted they were built for that.

“We feel comfortable once we get these to our lab in D.C. that we will be able to get a good readout of the applicable data,” Inman said. It will take at least several days before investigators can review what’s on the recorders, he added.

CBS News aviation safety analyst Robert Sumwalt, a former NTSB chair, said securing the black boxes is a top priority.

“They will be looking at the maintenance and inspection history, and then as time goes on, they will be looking at pilot training records to see how well-trained they were,” Sumwalt said.

The black boxes, which are actually bright orange to make them easier to spot, have a shell that’s made of hardened titanium or stainless steel with internal insulation to survive temperatures up to about 2,000 degrees Fahrenheit for at least one hour.

Jet fuel burns between 800 degrees and 1,200 degrees, but the plane came down in an industrial park, and materials there could have made the massive blaze burn hotter. The fire also burned for more than an hour. The NTSB has a good track record of recovering data even from badly damaged data and voice recorders.

The data recorder should give investigators a sense of how the 34-year-old converted airliner was operating in the moments leading up to the crash. The voice recorder should reveal what the pilots heard and said during the doomed takeoff.