It is the deadliest aviation accident involving the Swearingen Fairchild Metroliner.

Two minutes later, pieces of the Metro III impacted near Kettwig adjacent to the Ruhr River, killing all 21 people aboard.

[2] The investigation revealed that the aircraft had been hit by lightning during the approach to Düsseldorf Airport, which disrupted the electrical system and therefore the flight instruments.

The pilots became disorientated and blindly entered a high speed descent.

After almost 2 minutes of "predominantly uncontrolled flight," one of the trailing edge flaps (which could not be retracted without electrical power) failed due to overloading, sending the aircraft into an unrecoverable spiral during which it disintegrated in midair.