Subject (aircraft) + 在 + Location + 坠毁
坠毁 (zhuìhuǐ) means 'to crash' or 'to crash and be destroyed,' typically used for aircraft or spacecraft accidents. It conveys a sudden, catastrophic fall from the sky. For example, 飞机在山区坠毁 means 'The airplane crashed in the mountain area.'
那架直升机在山里坠毁了。
Nà jià zhíshēngjī zài shān lǐ zhuìhuǐ le.
That helicopter crashed in the mountains.
飞机坠毁的原因还在调查中。
Fēijī zhuìhuǐ de yuányīn hái zài diàochá zhōng.
The cause of the plane crash is still under investigation.
消息说有一架小飞机在海边坠毁。
Xiāoxi shuō yǒu yì jià xiǎo fēijī zài hǎibiān zhuìhuǐ.
Reports say a small plane crashed by the seaside.