Even if the people of The City of Enoch had surpassed far beyond Tubal-cain's discovery of bronze and iron (Genesis 4:22). Even if the people had advanced so far in metallurgy that they had invented a material stronger than any invented to this day. Even if they had used this material to build a magnificent dome over the entire city, such still would have been powerless to stop the flood.
The people of the City of Enoch could not outwork God, outsmart God, or outrun God. God sent the flood to blot out the pre-flood world, and no man would be strong enough to resist His mighty hand:
Then the flood came upon the earth for forty days, and the water increased and lifted up the ark, so that it rose above the earth. The water prevailed and increased greatly upon the earth, and the ark floated on the surface of the water. (Genesis 7:17-18)The flood came upon the earth for forty days. For forty days and forty night, the rain kept coming. Over these days, it seems that the fountains of the great deep also continued spewing out water (Genesis 7:11). The water prevailed. No man could endure the fierceness of the flood. No man could endure without the protection of Almighty God.
As the ark rose, The City of Enoch sunk. The city's ancient foundation was no protection against the judgment of God. The ark climbed higher and higher, but the city plunged deeper and deeper. Everything was destroyed— all human life totally perished, both in The City of Enoch and throughout the entire pre-world.
Evidence for a Global Flood: Water Above The Mountains (Part 1) - Genesis 7:19-20
Zero More Years of Mercy (Part 1) - Genesis 7:16
The Forger of All Implements of Bronze and Iron - Tubal-cain - Genesis 4:22
The City of Enoch - Genesis 4:17-18
Noah's Timely Entry (Part 1) - Genesis 7:13-15