Tennessee Valley Authority says that the sudden temperature changes are the reason thousands of dead fish have been found in several areas of Chattanooga Thursday.
"The Tennessee Wildlife Resources Agency (TWRA) is presently investigating the cause of the large numbers of dead fish seen in a wet weather conveyance that runs into the Tennessee River.
There are large numbers of dead threadfin shad throughout the region and we consider this to be a natural event outside of our control.
Authorities are investigating after thousands of dead fish were found in a creek off of Memphis Drive Thursday.
The Tennessee Wildlife Resources Agency (TWRA) says threadfin shad live in lakes, larger rivers, and reservoirs.