Following New Year’s Eve 2010 festivities in the Arkansas, US, city of Beebe, residents discovered between 4,000 and 5,000 dead birds.
According to the Arkansas Game and Fish Commission (AGFC), the birds all died as a result of bird trauma when flying into trees and buildings.
The AGFC speculated at the time fireworks were responsible for spooking the birds from their roosts but the source of their unrest was not conclusively determined.
The AGFC said: “It appears, unusually loud noises, reported shortly before the birds began to fall, caused the birds to flush from the large roost.
“Additional New Year’s Eve fireworks in the area may have forced the birds to fly at a lower altitude than normal.