Animal welfare experts in England are puzzled by the deaths of 75 starlings which apparently fell out of the sky and smashed into the ground.
The birds were found on the driveway of a home in Coxley, Somerset, with broken beaks, legs and wings as well as abdominal injuries.
RSPCA workers have begun investigating how the birds died but do not believe they were ill or poisoned before they fell from the sky.
Six of the birds were still alive when they were found but had to be euthanased because their injuries were too severe.
"It was a remarkable sight, I've never seen anything like it," animal welfare officer Alison Sparkes told the BBC.
"Onlookers said they heard a whooshing sound and then the birds just hit the ground.
"They had fallen on to the ground in quite a small area, about 12ft (3.6m) in diameter.
"They appeared to be in good condition other than injuries that they appear to have suffered when they hit they ground.
"Our best guess is that this happened because the starlings were trying to escape a predator such as a sparrow hawk and ended up crash landing."
The mystery about what happened to the birds is just as puzzling as what caused the deaths of thousands of crows, pigeons, wattles and honeyeaters which fell out of the sky in Esperance, Western Australia in 2007.
A few weeks later, dozens of grackles, sparrows and pigeons also dropped dead on the other side of the world in Austin, Texas.
The RSPCA believes it is possible that the birds found in England could have been chased by a predator but when they tried to swoop to escape, they flew too low and hit the ground.
The owner of the home where the dead birds were found, Julie Knight, described finding the creatures as "absolutely terrifying".
"It was like something out of a horror film, like Hitchcock's The Birds," she told The Daily Telegraph.
"The sky was raining starlings. One of my neighbours saw them. They seemed to just fall out of the sky.
"The only way to describe what they looked like is that they seemed to have had a fright and were petrified.
"I have been a country girl all my life and I've never seen anything like it."