I wonder if someone threw it or it just fell off a structure? The time it happened is odd, unless kids already have school off for the holiday, and were still out from the night before. Horrible crime if it was people who did it. I’ve dealt with youths rolling tires down a hill onto a highway with no place to pull off. I was luckily I saw them coming down.
From the excerpt...
"Inspectors with the Tennessee Department of Transportation determined that the concrete was not a part of the bridge structure, but more closely resembled a roadside curb, according to the statement."