Surah Al-Hajj, Verse 1:
يَا أَيُّهَا النَّاسُ اتَّقُوا رَبَّكُمْ إِنَّ زَلْزَلَةَ السَّاعَةِ شَيْءٌ عَظِيمٌ

O mankind! Fear your Lord and be dutiful to Him! Verily, the earthquake of the Hour (of Judgement) is a terrible thing.

Surah Al-Hajj, Verse 2:
يَوْمَ تَرَوْنَهَا تَذْهَلُ كُلُّ مُرْضِعَةٍ عَمَّا أَرْضَعَتْ وَتَضَعُ كُلُّ ذَاتِ حَمْلٍ حَمْلَهَا وَتَرَى النَّاسَ سُكَارَىٰ وَمَا هُم بِسُكَارَىٰ وَلَٰكِنَّ عَذَابَ اللَّهِ شَدِيدٌ

The Day you shall see it, every nursing mother will forget her nursling, and every pregnant one will drop her load, and you shall see mankind as in a drunken state, yet they will not be drunken, but severe will be the Torment of Allah.