I don't know where you're getting your facts, but according to Fall of Civilizations, it's not just one burnt down building, we're talking of a layer of ash, charred wood and burned material throughout the Eastern Mediterranean.
"The archeological evidence is quite clear: at some point between the year 1200 and the year 1100 BC, right at the end of the period we call the Bronze Age, a wave of destruction washed across the entire region. It wiped whole civilizations off the map and left nothing in its wake."
Yes, that’s the exaggerated tale that everyone knows.
In “Destruction and Its Impact on Ancient Societies at the End of the Bronze Age” <https://www.lockwoodpress.com/product-page/the-fall-of-the-b...> Jesse Millek examines 153 sites claimed to have been destroyed and found that 61% never happened, happened during a different time period, or had a different cause.
Even without buying the whole book you can download the appendix where he summarizes the results. A few notable entries:
Shiqmona: The possibly destroyed public building dates to the fourteenth century BCE. No end of the Late Branze Age destruction was uncovered.
Tell Irbid: C14 dates derived from short-lived samples places the destruction event between 1395–1260 BCE.
Krisa: There is only a statement that the site was destroyed with no published evidence of destruction in any structure.
Iria: Some burnt material in a pit was assumed to be a destruction. There was no damage visible to the buildings.
Athens: The Houses on the North slope were not houses at all. It was refuse that was dumped on the stairs.
Ayios Stephanos: Burning was uncovered in one room from Trench Beta 11. No other damage was recorded.
Amman Airport Structure: Evidence of burning in Room VII can be attributed to the hearth in that room.
Pefkakia: Adrimi-Sismani repeatedly cited a destruction, even though the excavators clearly stated the site was abandoned.
Tell el-‘Ajjul: Bell simply placed it on a map as destroyed with no citations. There was no settlement ca. 1200 BCE.