Update 10:30 p.m.: The National Transportation Safety Board says that a total of three bodies have been recovered from the Hudson; it is not clear whether the bodies are from the plane and/or helicopter. The diving recovery operations were called off in evening and will resume in the morning.

Additionally, Mayor Bloomberg's plans to "Tweet for a day" tomorrow (for his re-election campaign) have been postponed: "Due to the events surrounding the tragic air accident over the Hudson river on Saturday 8/8, Mayor Bloomberg will not be personally tweeting Sunday 8/9 as originally announced. As all New Yorkers can surely appreciate, the Mayor is focused on the response to this accident. His thoughts and prayers are with the families and loved ones of the victims."

Update, 7:20 p.m. : Divers continue to search as only two bodies and neither aircraft has been pulled out of the water. Ray Kelly told reporters that another helicopter pilot on the ground at the heliport for Liberty Tours saw the plane approaching the helicopter and tried to radio an alert to the pilots, but the warning wasn't heard or didn't happen in time.

Updated, 4:20 p.m. : Officials are now saying that all nine passengers are believed to be dead as divers continue to search for the remaining bodies in the Hudson River.

Updated, 3:30 p.m. : Two bodies have been recovered after a small plane collided into a helicopter over the Hudson, sending its passengers into the river. The accident took place around noon in the vicinity of 14th Street. Mayor Bloomberg just said, "This has changed from a rescue to a recovery mission," and said the crash was "not survivable." The Liberty Tour helicopter had a pilot and five passengers—Italian tourists—while it's believed the small plane had three people (a pilot and two passengers, one of whom was a child) aboard—Bloomberg added, "This is not going to have a happy ending."

The NY Times reports, "Witnesses said the airplane, a single-engine Piper PA-32R-300 that had taken off from Teterboro Airport in New Jersey and was flying south along the river, appeared to lose control as it banked steeply to the left and struck the Liberty Harbor Sightseeing Tours helicopter not far off the shoreline in Hoboken, N.J."

One witness watched both aircrafts spiral down into the Hudson and told NY1, "Then it just disappeared.... You couldn't believe it. You couldn't see anything left in the water." The small plane was reportedly lost to radar after taking off from Teterboro Airport, according to WCBS 2.

Divers are in the Hudson River, looking for bodies and wreckage, but the Hudson's murky conditions are causing visibility issues—they can only see 1-3 feet in front of them. Mayor Bloomberg said that National Transportation Safety Board would investigate.

We're hearing that the black box was recovered near Hoboken. And in 2007, a Liberty Travel helicopter crashed into the Hudson soon after takeoff; the chopper had been experiencing engine problems (no one was seriously hurt).