After they refused to believe, they suffered from severe famine, then a huge black cloud appeared above their land. Allah (swt) says:

 فَلَمَّا رَأَوْهُ عَارِضًا مُّسْتَقْبِلَ أَوْدِيَتِهِمْ قَالُوا هَٰذَا عَارِضٌ مُّمْطِرُنَا ۚ بَلْ هُوَ مَا اسْتَعْجَلْتُم بِهِ ۖ رِيحٌ فِيهَا عَذَابٌ أَلِيمٌ (24) تُدَمِّرُ كُلَّ شَيْءٍ بِأَمْرِ رَبِّهَا فَأَصْبَحُوا لَا يُرَىٰ إِلَّا مَسَاكِنُهُمْ ۚ كَذَٰلِكَ نَجْزِي الْقَوْمَ الْمُجْرِمِينَ (25)

((24) And when they saw it as a cloud approaching their valleys, they said, “This is a cloud bringing us rain!” Rather, it is that for which you were impatient: a wind, within it a painful punishment, (25) Destroying everything by command of its Lord. And they became so that nothing was seen [of them] except their dwellings. Thus do We recompense the criminal people.) (Al-Ahqaf)

Along comes a great black cloud carrying a screaming and violent wind, which utterly destroyed everything to the extent that nothing could be seen save except their empty dwellings.

( فَأَنجَيْنَاهُ وَالَّذِينَ مَعَهُ بِرَحْمَةٍ مِّنَّا ) (So We saved him and those with him by mercy from Us): Allah (swt) saved Prophet Hud (PBUH) and the believers who were with him by His Mercy (swt).

( وَقَطَعْنَا دَابِرَ الَّذِينَ كَذَّبُوا بِآيَاتِنَا) (And We eliminated those who denied Our signs): The disbelievers were eliminated, which means their existence and lineage were wiped out and they perished from the worldly life.