NEW YORK -LRB- CNN -RRB- -- Five Italian tourists visiting New York from Bologna are among the nine victims believed killed Saturday in a midair collision of a sightseeing helicopter and a single-engine plane over the Hudson River , a law enforcement source said . First responders gather on a pier after a plane and helicopter collided Saturday over the Hudson River . The tourists , who apparently died with the chopper 's pilot , were part of a group of 12 visiting the United States , the source said . The helicopter was operated by Liberty Helicopter Sightseeing Tours . The bodies of two adults and one child were recovered after the collision , which occurred around noon over the Hudson between New York and Hoboken , New Jersey , authorities said . The child is believed to be one of the three people on the plane , a single-engine Piper PA-32 Saratoga that took off from New Jersey 's Teterboro Airport , authorities said . A source involved in the investigation identified the pilot and owner of the plane as Steven Altman , whose brother Daniel and nephew Douglas also were among the victims . The two adult bodies , discovered underwater , are believed to be two of the Italian tourists aboard the helicopter , the law enforcement source said . The Italian Foreign Ministry said consulate officials were working with New York authorities to identify the victims . Helicopter wreckage was found in about 30 feet of water , while the plane is believed to be near the midchannel point of the Hudson in deeper water , the source said . A side-scanning sonar is being used to pinpoint the plane and has identified a possible third debris field , the source said . The search is scheduled to resume Sunday morning , Debbie Hersman , chairwoman of the National Transportation Safety Board said at a riverside news conference late Saturday . Underwater visibility of about two feet hampered Saturday 's search effort , she said . All nine people in both aircrafts are thought to have been killed in the collision , New York Mayor Michael Bloomberg said . See where the collision occurred '' `` There was an accident which we do not believe was survivable , '' said Bloomberg , noting that the search for survivors had become a recovery mission . A temporary flight restriction over the rescue area -- about three nautical miles around and 2,000 feet up -- was put in place , a Federal Aviation Administration spokeswoman said . A witness told investigators he saw the airplane approach the helicopter from behind , Hersman said . The witness said the plane 's right wing made contact with the helicopter , an American Eurocopter AS350 operated by Liberty Helicopter Sightseeing Tours , Hersman said . View images from the scene '' Another Liberty pilot who was refueling at a nearby heliport told NTSB investigators that he saw the plane approach the helicopter and tried to warn the helicopter pilot , but got no response , Hersman said . `` This is a VFR corridor -- that means Visual Flight Rules prevail , '' Hersman told reporters late Saturday . `` You are supposed to be alert and see and avoid other aircraft in the vicinity . '' iReport.com : Police search for debris Witnesses reported seeing debris flying from the helicopter as it crashed . The helicopter wreckage has been found , but the search for the plane , single-engine Piper Saratoga PA-32 , will continue Sunday morning , Hersman said at a riverside news conference . Witness Arnold Stevens said after the plane had a wing sheared off , it began `` corkscrewing '' into the water . The helicopter `` dropped like a rock '' after the collision , which happened about noon . See a series of photos from the scene '' Radar contact was lost with a small plane this morning believed to be the aircraft in the crash , FAA spokeswoman Arlene Salac said . Ben Berman , a former investigator with the National Transportation Safety Board , said if the helicopter fell straight down , it 's likely there was a rotor failure . Scott Schuman was with his grandparents on the Hoboken side of the river when they heard a loud bang . `` The plane was kind of whirlybirding its way down , brown smoke coming out the back of it , and it crashed into the water . Then a few seconds later the helicopter with debris falling off of it also hit as well , '' Schuman said . `` It was a scary sight , '' he added . iReport.com : Were you there ? Send images He said some of the debris fell in Hoboken , and `` we covered our heads . '' Asked if he had seen anyone in the water , Schuman replied , `` I have not seen anything , but judging by the impact when the plane and the helicopter hit , it would be very unlikely for a positive outcome . '' Hoboken Mayor Dawn Zimmer called on witnesses who filmed or photographed the incident to come forward . `` It would be extremely helpful to have that footage , '' she said . The busy airspace surrounding New York 's Manhattan island has been the site of several aeronautical mishaps in recent history . Earlier this year , a US Airways plane with 155 people on board ditched into the Hudson , apparently after striking at least one bird upon takeoff from New York 's LaGuardia Airport , officials said . Capt. Chesley B. `` Sully '' Sullenberger 's landing , which resulted in no deaths or serious injuries , was captured on closed circuit television . In 2006 , Yankees pitcher Cory Lidle and his flight instructor were killed when the 34-year-old ballplayer 's plane crashed into a high-rise apartment building near the East River , city officials said . CNN 's Susan Candiotti contributed to this report .