Cameroon ? Three jetliners sat ready for takeoff at Douala International Airport, their crews waiting for a massive thunderstorm to move away.

Just a few minutes past midnight, all three radioed air traffic control to check the weather report. They were told the storm would take another hour to dissipate, and the Cameroon Airlines and Royal Air Maroc crews opted to wait it out.

But Capt. Francis Mbatia Wamwea of Kenya Airways Flight 507, already delayed for an hour and carrying scores of passengers with onward connections to catch, judged the weather had improved sufficiently to permit departure for Nairobi, Kenya.

Less than a minute after takeoff early on May 5, the Boeing 737-900 slammed into a jungle swamp during a raging storm, killing all 105 passengers and the nine-member crew.

Wamwea’s decision to depart into one of the violent tropical storms that regularly ravage equatorial Africa during the rainy season was most likely the pivotal factor in a sequence of events that led to the crash, according to two crash investigators.