A huge flock of birds plummeted to the ground in Mexico in a mysterious incident captured by a security camera.
In the unsettling video, a flock of yellow-headed blackbirds passes over a neighborhood in Chihuahua, in northern Mexico, when they all plunge suddenly toward the earth.
Some of the birds fly away, but many appear to have died on impact. A person on the scene shared a video of several birds lying on the pavement.
The reason behind the flock’s sudden fall has not been determined, but some experts believe the blackbirds were migrating south from Canada and were being chased by a bird of prey.
They may have swooped down en masse to avoid the predator, but weren’t able to pull up in time.
One veterinarian also says the birds may have hit power lines or inhaled toxic fumes from a heater, according to NBC News.