ついらく墜落tsuiraku
1.

The act of falling from a significant height, often associated with loss of control, such as an aircraft descending unexpectedly.

2.

A rapid decline from a previously elevated state, indicating a significant downturn in fortune or success, as in a fall from grace.

Example:

上へ昇れば昇るほど、それだけ墜落の程度は大きくなる。

ついらくじこ墜落事故tsuirakujiko
1.

An incident in which an aircraft unexpectedly descends uncontrollably, resulting in a collision with the ground or another object, often causing damage and casualties.

2.

A catastrophic event involving the failure of an aircraft during flight, leading to its sudden and often disastrous landing.

3.

A serious aviation occurrence where an aircraft loses altitude rapidly and crashes, typically causing significant destruction and loss of life.

Example:

その墜落事故で400人もの乗客が死亡した。