undetermined origin meaning in English

未明来源,原因未定
原因未定

In 1997 , an explosion of undetermined origin killed a passenger who was blown out of a tam fokker 100 during flight
1997年，该公司的另一架福克尔100在飞行途中爆炸，导致一名乘客在被甩出飞机后身亡，而爆炸原因至今尚未查明。
In 1997 , an explosion of undetermined origin killed a passenger who was blown out of a tam fokker 100 during flight . in 2001 an engine breakup on a tam fokker 100 caused two cabin windows to shatter and one of 82 passengers aboard died as a result of the depressurization
2001年，还是tam公司旗下的一架载有82名乘客的福克尔100飞机因发动机故障致使两块机舱窗户的玻璃破碎，致使一名乘客因舱内气压下降而死亡。