If sky/samaa is understood to be outerspace/universe/mulitple galaxies in the Quranic verses below then it is appropriate to conclude that a falling sky could be interpreted as celestial bodies( meteors/asteroids) from outer space colliding with our planet.
If sky/samaa is understood as atmosphere or spiritual domain in the Quranic verses below then extensive research should be done both from a scientific and theological perspective to have an understanding of theses verses
(Quran 34 9)
Then, do they not look at what is before them and what is behind them of the heaven and earth? If We should will, We could cause the earth to swallow them or [could] let fall upon them fragments from the sky. Indeed in that is a sign for every servant turning back [to Allah].}
(Quran 22 65)
Do you not see that Allah has subjected to you whatever is on the earth and the ships which run through the sea by His command? And He restrains the sky (السماء) from falling (تقع) upon the earth (الارض), unless by His permission. Indeed Allah, to the people, is Kind and Merciful.
(Quran 17 90-92)
“We will never believe in you until you cause a spring to gush forth from the earth for us,or until you have a garden of palm trees and vineyards, and cause rivers to flow abundantly in it,or cause the sky to fall upon us in pieces, as you have claimed, or bring Allah and the angels before us, face to face or until you have a house of gold, or you ascend into heaven—and even then we will not believe in your ascension until you bring down to us a book that we can read.” Say, “Glory be to my Lord! Am I not only a human messenger?”
(Quran 52 44)
And if they were to see a fragment from the sky falling, they would say, “[It is merely] clouds heaped up.”
Allah SWT knows best