HUDSON RIVER, NEW YORK CITY - Federal investigators say both engines on the US Airways jetliner that made an emergency landing in the Hudson River are missing.

Kitty Higgins of the National Transportation Safety Board said Friday that police divers are using sonar to search the river for wreckage from the engines.

Other crews are rigging up the aircraft in preparation to be pulled from the river tomorrow morning. The plane will be placed on a barge and moved to a secure location for further investigation.

Authorities are also working to recover the flight data recorder and cockpit voice recorder from the tail section of the airplane.

It is not known if the engines separated on impact or detached after the emergency landing, CBS News correspondent Bob Orr.

Experts say it's not uncommon for engines to break apart from planes after bird strikes, because of the severe vibration brought on in such incidents.

This somewhat complicates the investigation in that the NTSB will need to examine each engine for signs of bird strikes to confirm the theory that birds caused a double engine failure, reports Orr.

Higgins outlined the NTSB's plans to interview the pilots, in-cabin flight crew, air traffic controllers and some passengers over the next several days. Some of those interviews are already underway, she said.

She added, "We are working with both with the FBI and the city and others to retrieve all video evidence that might have been captured in various kinds of cameras and recorders - up and down the river."

Higgins said she was aware of the widespread reports of the crash being caused by bird strike, but would not speculate on the crash until the investigation has taken place.

"If in fact there was any kind of damage as a result of birds being ingested, my understanding is that will show up - the forensics will help tell us that - so, it's a very important piece of the puzzle," she said.

Whatever happened, it's increasingly clear that the pilots - facing a double-engine failure at a critical moment in flight - made all the right moves and the key split-second decisions to ward off catastrophe, Orr reports.

The plane began dropping over the Hudson River losing altitude, bleeding off speed as it crossed 900 feet above the George Washington Bridge. Just 300 feet above the water and still traveling at 176 mph, the pilots raised the nose, preventing a wing or engine from catching the water first and causing the plane to cartwheel, Orr reports.

Water landings are rare - and dangerous. Only a few commercial flights have ever deliberately ditched. In 1996 a hijacked Ethiopian Airlines jet tried to land on the Indian Ocean. Two-thirds of the people on board were killed.