About Kenya Airways flight 507:

A Boeing 737-800 passenger plane, registered 5Y-KYA, was destroyed when it impacted terrain shortly after takeoff from Douala Airport (DLA), Cameroon. All 108 passengers and six crew members were killed in the accident.
The airplane was operated by Kenya Airways as flight KQ507 from Abidjan Airport (ABJ), Ivory Coast to Nairobi (NBO), Kenya via Douala (DLA), Cameroon. The flight from Abidjan to Douala was reportedly conducted without incident.
The flight arrived about 22:00 hours local time, May 4. The scheduled departure time of 23:00 was delayed due to weather which consisted of thunderstorms with heavy rain showers. When the weather improved, flight 507 taxied to runway 12. The aircraft took off and climbed into the dark night. There were no external visual references, yet no instrument scanning was done by the crew. At 1000 feet climbing, the pilot flying released the flight controls for 55 seconds without having engaged the autopilot. The bank angle of the airplane increased continuously by itself very slowly up to 34 degrees right and the captain appeared unaware of the airplane?s changing attitude.
Just before the "Bank Angle" warning sounds, the captain grabbed the controls, appeared confused about the attitude of the airplane, and made corrections in an erratic manner increasing the bank angle to 50 degrees right.
At about 50 degrees bank angle, the autopilot was engaged and the inclination tended to stabilize; then movements of the flight controls by the pilot resumed and the bank angle increased towards 70 degrees right. A prolonged right rudder input brought the bank angle to beyond 90 degrees. The airplane descended in a spiral dive and crashed into a mangrove swamp.

Probably cause:

The airplane crashed after loss of control by the crew as a result of spatial disorientation (non recognized or subtle type transitioning to recognized spatial disorientation), after a long slow roll, during which no instrument scanning was done, and in the absence of external visual references in a dark night.
Inadequate operational control, lack of crew coordination, coupled with the non-adherence to procedures of flight monitoring, confusion in the utilization of the AP, have also contributed to cause this situation.