Two people have died after the small aircraft they were flying in crashed into a high-rise apartment block in New York City's affluent Upper East Side.
The crash sent flames pouring out of the building
The two killed were New York Yankees baseball pitcher Cory Lidle and his flying instructor, officials from the baseball club said.
The plane's impact caused a fireball, which set two floors of the 50-storey building on Manhattan island ablaze.
Despite initial fears of terrorism, the crash is being treated as an accident.
Lidle is believed to have been flying the plane
The New York Fire Department said the aircraft struck the 20th floor of the building on East 72nd Street and York Avenue - identified as the Belaire, a prestigious residential tower.
Local resident Mark Schaffer told the BBC News website that he saw the moment the Cirrus SR20 hit from his building across the street.
"I looked up when I heard a low flying plane and saw it as it crashed," Mr Schaffer said. "The rear half of the plane broke off and fell to the ground in flames. Glass sprayed out everywhere and people were screaming."
The plane was owned by Lidle, whose passport was found at the scene of the crash, police officials said.
"This is a terrible and shocking tragedy that has stunned the entire Yankees organisation," baseball club owner George Steinbrenner said in a statement confirming the player's death.
"I offer my deep condolences and prayers to his wife Melanie and son Christopher on their enormous loss."
The impact of the plane caused a loud noise and sent burning debris plummeting down onto the street below.
Over 100 emergency workers rushed to the scene, while firefighters shot streams of water at the flames from the lower floors.
A New York police spokesman said that the while suicide could not be ruled out, there was nothing to suggest that this had been the cause of the crash, which is being investigated as an accident.
In a press conference shortly after the crash, New York Mayor Michael Bloomberg sought to quell fears of any connection to a terrorist attack.
"There is nothing to suggest that anything remotely like terrorism was involved in this," he said.
Nonetheless fighter planes were scrambled over several cities across the US in the aftermath of the crash.
And the incident has evoked memories of the 11 September 2001 attacks on the World Trade Center for many New Yorkers.
Witness Joshua Asquith told the BBC News website: "Everybody was really shocked here, we thought of a terrorist attack. There was also a lot of noise and dust around here, causing an atmosphere of terror and fear."
Roger Gosden, another eyewitness, told the BBC that "everyone in the street looked up [after hearing the crash], perhaps having flashbacks of 9/11".
On Wall Street, stocks initially fell on news of the crash, but quickly recovered when it became clear that the incident was most likely an accident.