For those still wondering why thousands of birds died in Beebe, Ark., on New Year’s Eve and thousands more fish washed up dead around the same time in a river to to the west near the Oklahoma border:

— The Arkansas Game and Fish Commission says “three laboratories’ test results on red-winged blackbirds that died in Beebe’s Windwood neighborhood Dec. 31 show the cause of death was blunt-force trauma.”

It adds that “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. Blackbirds have poor night vision and typically do not fly at night.”

The startled birds crashed into things — trees, buildings, utility poles — and died.

— But the commission says that “the exact cause of the Arkansas River fish kill that took place on Dec. 29, 2010, still eludes biologists.” They’ve been able to rule out bacterial and viral infections. Toxins do not appear to be to blame.

“Unfortunately, we probably will never know exactly what killed these fish,” said AGFC Assistant Chief of Fisheries Chris Racey. “But the testing has eliminated the largest public concerns of disease, parasites and toxins. We have no reason to think fish caught in the Arkansas River are unsafe to eat.” Copyright 2011 National Public Radio. To see more, visit http://www.npr.org/.