In the fifth verse (84), the punishment which came on these people has been described in a few words - that an unusual rain was sent upon them. The details of this punishment appear in Surah Had where it is said:
فَلَمَّا جَاءَ أَمْرُنَا جَعَلْنَا عَالِيَهَا سَافِلَهَا وَأَمْطَرْنَا عَلَيْهَا حِجَارَةً مِّن سِجِّيلٍ مَّنضُودٍ ﴿82﴾ مُّسَوَّمَةً عِندَ رَبِّكَ ۖ وَمَا هِيَ مِنَ الظَّالِمِينَ بِبَعِيدٍ ﴿83﴾
(So, when Our command-came, We turned its highest into its lowest, and We rained on it stones of hard clay, one over an-other marked, with your Lord. And they are not far from the transgressors - 11:82-83).
This tells us that the rain of stones came from above and from down below, angel Jibra'il (علیہ السلام) lifted up the whole crust of the earth and threw it back upside down. Then, the stones which rained down were one over the other, that is, the stone rained so ceaselessly that they kept collecting one on top the next. These stones were marked. Some commentators say that every such stone was marked with the name of the person who was destined to be destroyed with it. And in the verses of Surah Al-Hijr, also mentioned before the account of the punishment is: فَأَخَذَتْهُمُ الصَّيْحَةُ مُشْرِقِينَ ﴿73﴾ that is, a Sound seized them at sunrise - 15:73).
This indicates that first to come was some harsh Sound from the skies, then came other punishments. The outward arrangement of the words shows that it was after this Sound that the earth crust was turned upside down and then, stones were rained on them to put a stamp on their disgrace. And it is also possible that the rain of stones came first and the turning over of the earth crust came later. The reason is that, given the style of the Qur'an, it is not necessary that some-thing mentioned earlier should have also occurred earlier.
Out of the horrendous punishments sent on the people of Sayyidna Lut (علیہ السلام) ، the punishment of turning the floor of the earth upside down has a particular correspondence with their act of shame and immodesty because they were guilty of perversion.
Towards the end of the verses of Surah Hud cited a little earlier, the Qur'an has warned the people of Arabia when it says: وَمَا هِيَ مِنَ الظَّالِمِينَ بِبَعِيدٍ ﴿83﴾ that is, these upturned habitations were not far from the transgressors. They pass by them while traveling to Syria but it is surprising that they would learn no lesson from them.
And these sights are not restricted with the time the Holy Qur'an was being revealed. They are still there between Bayt al-Maqdis and Jordon river, particularly the area known as the Sea of Lut or the Dead Sea. It lies way deep below the sea level. On a particular section, there is water which is unusual. No sea life survives there. Hence, the name: Dead Sea. This is said to be the legendary Sodom. May Allah keep us safe from His Punishment and Wrath.