National Transportation Safety Board officials arrived in New York City to begin the official federal investigation of the New York City sightseeing helicopter that broke apart in midair on Thursday and crashed into the Hudson River,

Six people were killed on April 10 when a sightseeing helicopter plummeted into the Hudson River upside down, officials said.

The helicopter that crashed into New York City's Hudson River on Thursday, killing all six on board including three children, lacked flight recorders, the National Transportation Safety Board said. No video or camera recorders have been recovered from the Bell 206 helicopter,