A UPS cargo plane’s left wing caught fire and an engine fell off just before it crashed and exploded after takeoff in Kentucky, a federal official said Wednesday, offering the first investigative details about a disaster that killed at least 12 people, including a child.

Finding survivors seemed unlikely as first responders searched the charred area of the crash at UPS Worldport, the company’s global aviation hub in Louisville, Gov. Andy Beshear said. The inferno consumed the enormous aircraft and spread to nearby businesses.

Surveillance footage from a nearby truck parts business shows large flames and plumes of smoke as the plane hits the ground.

After being cleared for takeoff, a large fire developed in the left wing, said Todd Inman, a member of the National Transportation Safety Board, which is leading the investigation. The NTSB will now try to determine what caused the fire and why the engine fell off. It will likely take investigators more than a year to answer those questions.