It is sometimes difficult to say how you feel in unexpected situations, such as natural disasters, especially when you feel sad. Here's a list of some common expressions to help you express shock and disbelief.

Shock

I was shocked to hear…
The news came as a complete shock.
We're all in complete shock.
Everyone's reeling from the shock of…
It happened out of the blue.
Who could have predicted it?
I (just) can't get over ….
We were completely taken aback by…
I was just stunned by…

Disbelief

I just can't believe…
It's unbelievable.
I / You just can't imagine…
Words can't describe… (how I feel about / the terrible devastation etc)
There's no way it could have happened.

Saying how bad something is

It's so awful.
It's terrible / What terrible news.
It's a tragedy.
It's a catastrophe (pronounced "ca – tas – tra – fee" with the stress on "-tas")
This is the worst thing that could have happened.

日常口语