A New York teenager was killed when a remote control helicopter he was piloting struck him in the head and neck, leaving him almost decapitated.
Roman Pirozek, 19, was flying the helicopter in Calvert Vaux Park in Brooklyn when the accident happened.
According to reports the blades sliced off part of his skull and slashed his throat.
It is thought that Mr Pirozek, who was an avid helicopter enthusiast and member of the Seaview Rotary Wings, a Brooklyn-based club for model helicopter enthusiasts, lost control while attempting a stunt.
Paramedics worked desperately to save his life as onlookers, including his father Roman Snr, watched horrified. Despite the efforts of emergency services it is thought he died instantly in the accident.
Video footage has emerged of Mr Pirozek, who was a world-recognised aerobatic flyer, putting his Trex 700 helicopter through a series of remarkable tricks, including one that involves dropping the $1,500 model out of the sky by turning off the engines and restarting them just before the model chopper hits his head.
Police told the Wall Street Journal that Mr Pirozek “was known to be aggressive in his flying and often executed tricks," and that "he was executing a trick when he was struck".
The Trex 700 remote control helicopter has a blade span of 62 inches, weighs just over six pounds and has a rotor that spins at more than 2,000rpm.
Mr Pirozek, who lived in Woodhaven, Queens, was a graduate of the High School for Construction Trades, Engineering and Architecture in Queens, New York.