There are always certain things about history that aren't clear, especially in Bible history. This is because history such as the Tower of Babel happened way before civilization started, there are a lot of theories as to what happened during that period which it's impossible to know unless witnessed.
It was written in Gen 11:1-8(NIV)
Now the whole world had one language and a common speech. As people moved eastward, they found a plain in Shinar and settled there.
They said to each other, “Come, let’s make bricks and bake them thoroughly.” They used brick instead of stone, and tar for mortar. Then they said, “Come, let us build ourselves a city, with a tower that reaches to the heavens, so that we may make a name for ourselves; otherwise we will be scattered over the face of the whole earth.”
But the Lord came down to see the city and the tower the people were building. The Lord said, “If as one people speaking the same language they have begun to do this, then nothing they plan to do will be impossible for them. Come, let us go down and confuse their language so they will not understand each other.”
So the Lord scattered them from there over all the earth, and they stopped building the city. That is why it was called BABEL because there the Lord confused the language of the whole world. From there the Lord scattered them over the face of the whole earth.
I believe there is a rather physical and more rational approach to what occurred here, I like to be practical in my approach to things, from the seven wonders of the world (if you have read about them) It seems to be that there were civilizations more advanced than anything we have ever seen or imagine, in both technology and way of living.
I have a personal theory that they were more advanced men before those who we know as ancient men that lacked civilization. And the Tower of Babel is what I presumed to be one of such scenario. Let's be practical here, we all know heaven isn't the sky we see, building a tower to reach God, is building something way over the dimensions or imaginations of men.
Many will easily want to see this from a spiritual perspective, but claiming to be spiritual isn't the best approach to cover up what we clearly don't know. One thing is certain, they were building something that if allowed to be built could change the entire concept of life, we don't know what that is, we only know they failed in building it, and the only way to ensure such knowledge is sealed for all ages is to ensure it could never be passed.
But then lame men don't just come up with such inventions, what was it they knew, what was it that could have happened if Barbel wasn't destroyed, I guess we will never get to know, and if I'm privileged to go back in history as a witness, it will certainly be about this.