Flight 302 — a two-hour shuttle between two of the busiest capitals in East Africa — was carrying passengers from at least four continents. The dead included 32 Kenyans, 18 Canadians, nine Ethiopians, eight each from the United States, China and Italy, and seven from Britain, the airline said. The French Foreign Ministry said nine of its citizens were aboard.

The passengers also reportedly included delegates traveling to Nairobi for a weeklong United Nations Environment Assembly that was scheduled to start on Monday.

[Read more about who the victims were and where they were from.]

While the cause of the crash was unclear, the disaster is certain to raise more doubts about the safety of the 737 Max 8, one of Boeing’s fastest-selling airplanes.

The plane, delivered to Ethiopian Airlines in November, was new, just like the Lion Air airplane that plunged nose down into the Java Sea last October, minutes after taking off from Jakarta, the Indonesian capital.

Flight 302 took off in good weather, but its vertical speed became unstable right after takeoff, fluctuating wildly, according to data published by FlightRadar24 on Twitter. In the first three minutes of flight, the vertical speed varied from zero feet per minute per hour to 1,472 to minus 1,920 — unusual during ascent.

“During takeoff, one would expect sustained positive vertical speed indications,” Ian Petchenik, a spokesman for FlightRadar24, said in an email on Sunday.