Hoboken, N.J. ? Divers pulled a helicopter and four more bodies out of the murky Hudson River on Sunday in their search for victims, wreckage and explanations from a midair collision of a sightseeing helicopter and a small plane that killed nine people.

The dead from Saturday’s crash include three fathers and their three teenage sons. The private plane carried a family from Pennsylvania, and the helicopter held five Italian tourists celebrating a couple’s 25th wedding anniversary.

The plane approached the helicopter, which had just taken off for a 12-minute tour, from behind and clipped it with a wing, witnesses said. Both aircraft split apart and fell into the river.

Searchers fought swift currents, dealt with visibility as low as one foot, and dodged debris dumped along the river bottom as they brought four more bodies on to boats. One was found in the fuselage of the helicopter, New Jersey State Police Sgt. Stephen Jones said. The bodies of the plane’s pilot and an adult passenger remained missing, New York police spokesman Paul Browne said.

A U.S. Army Corps of Engineers crane lifted the twisted wreckage of the helicopter from 30 feet of water. Nearby, a sonar scanner found the small plane wreckage, New York City police said. More plane wreckage was found farther out in the river under about 50 feet of water.

The collision happened in the same stretch of the Hudson where a US Airways jet landed safely seven months ago. It was the worst air disaster in New York City since a commercial jet crash in Queens killed 265 people in November 2001.

The searches went on as a steady stream of tour boats floated down the Hudson. Restrictions put in place after the crash kept sightseeing helicopter tours grounded Sunday.

Divers suspended their search at about 6 p.m. Sunday and it will resume this morning, National Transportation Safety Board spokesman Keith Holloway said.

Investigators from the National Transportation Safety Board were reviewing flight data from the Teterboro Airport, where the plane took off a little before noon on Saturday.

The plane was not required to have a flight plan and did not file one, said NTSB Chairman Debbie Hersman.

The plane was flying at about 1,100 feet at the time of the crash, she said. Below that altitude, planes in that part of the Hudson River corridor are to navigate visually. Above that, they need clearance from air traffic controllers.

The control tower at Teterboro handed off responsibility for the plane to the tower in Newark about a minute before the crash and told the pilot to contact Newark controllers, Hersman said. But the Newark officials never heard from the pilot.

Additionally, investigators were asking witnesses to provide photos and video capturing the crash.