I wasn't inspired by the synopsis (hospital medical teams, firefighters, politicians, etc. dealing with a big earthquake in Seoul), so I put off watching this high-ranked drama for a long time.
Well, it totally deserves all the praise it's received... At least!

The story is coherent, well conducted, the psychology of the characters, their words, their behavior, are realistic. The themes addressed, subtly, are broad: life, suffering, death, mourning, courage, solidarity, sacrifice, meaning of life...
The cast is great, with wonderful actors, all of them including the many secondary characters.
Now let's talk about the CL. They have intense interactions, an extraordinary complicity (despite the all too rare intimate or cute moments). OK, the ML has a ridiculous hairstyle, but even so, he's adorable!
My only regret is that the ending was a little too abrupt. I would have liked to see the CL be finally peaceful, more intimate longer.

The music, epic, sometimes grandiose, is worthy of the circumstances.
The sets, the special effects are realistic, including the disaster scenes. The production is dynamic (nothing superfluous, no length, etc.).

Watch this drama without hesitation (don't do like me :), you will go through all the emotions, smile, fear, anguish, sadness (the death of the little brother brought me to tears and yet I don't cry often), nervousness , anger,... And like me, you will find it hard to leave these characters.

I will certainly watch it again and I strongly recommend it to all those who are not afraid to stay 2 days glued to their screen (because it will be the case from the viewing of the 1st episode).