Birdwatchers who gathered for a glimpse of the "bird of the century" watched in horror as it flew straight into a wind turbine in Scotland.
Crowds of twitchers went to the remote Western isle of Harris to see the Needletail, which has been spotted in Britain just five times in 60 years.
But their trip ended in horror when the rare creature careered straight into the turbine's rotating blades.
The needletail, which can fly at 105mph, was killed instantly on impact with the energy generating giant, more generally regarded as environmentally friendly.
Nick Moran had tracked the bird's journey across the world from where it breeds in Australasia.
He said: "It is not the happiest ending for a bird that has flown halfway around the world."
Birdspotting website, rarebirdalert.co.uk told IBTimes UK called the accident tragic. The site had dubbed it the "bird of the century".
A spokesman said: "It's very rare in Britain because it was here by accident. The needletail is a very exciting bird which has held the record for straight-line flight.
"It's tragic to see something beautiful and wonderful which has given so much pleasure come to an end like this. It's such a spectacular bird."
James Hanlon was among the group of enthusiasts who witnessed the bird's grisly death.
Some enthusiasts had even chartered private planes to make sure they did not miss out, he said.
Hanlon said: "One minute it was flying in spectacular fashion. I followed it and then watched as it flew into one of the blades of the wind turbine and vanished.
"My heart jumped into my mouth. We dashed over to see if it had been killed and sadly found its body on the ground. It was heartbreaking.
"We had a wonderful feeling of elation watching it - this bird has to rate in the top five of any UK twitcher's dream list. To see it die was absolutely shocking.
"There were hundreds on their way to see it. Some even chartered planes to take them to Stornoway so they could get here as soon as possible. They will have been devastated."