SHAW AIR FORCE BASE, S.C. - Authorities say an Air Force pilot had no opportunity to eject after a collision between two F-16 fighter jets offshore, and Coast Guard searchers say they've shifted efforts to finding his body and recovering the plane's wreckage.

A search for Capt. Nicholas Giglio, missing since Thursday night's crash, had involved Coast Guard helicopters, ships and private volunteers scouring about 8,000 square miles of Atlantic waters. Authorities said Saturday investigators believe Giglio died instantly during a night training exercise.

The Coast Guard had spent nearly two days conducting the search for the pilot in waters about 40 miles northeast of Charleston. Capt. Michael McAllister, director for the search, described that effort as exhaustive.

The search covered about 4,000 square miles. Coast Guard units from the Carolinas, Florida, Georgia and Virginia were involved in the search, along with helicopters and airplanes from Air Force bases in Georgia and Florida.

"If Capt. Giglio had ejected safely from the aircraft, we're confident we would have found him," McAllister said.

The other pilot was uninjured and landed his F-16 safely at Charleston Air Force Base.

Air Force Col. Joe Guastella said Saturday that investigators believe the bottom of the other jet struck the top of Giglio's fighter and pierced the pilot's canopy.

He said the collision occurred after Giglio and the second pilot, Capt. Lee Bryant, had finished most of their maneuvers and were getting ready to head home. Guastella added that radio beacons on the missing aircraft and pilot were never activated, indicating Giglio never left the cockpit.

"He had no opportunity to eject from the aircraft," Guastella said.

Investigators came to their conclusion using data gathered from the second jet and an interview with Bryant, whose flight controls weren't damaged, Guastella added.

The two pilots were part of Shaw Air Force Base's 20th Fighter Wing commanded by Guastella.

Giglio has been a fighter pilot for 18 months and part of the 77th Fighter Squadron training for a scheduled deployment to Iraq early next year. Originally from New Jersey, the 32-year-old pilot leaves behind a wife, a young daughter and a baby on the way, Guastella said.

Officials said there were reports of debris and an oil slick in the water after the crash, but investigators haven't determined if that came from Giglio's jet. The water is about 50 feet deep in the area where the Air Force thinks the F-16 went down, according to authorities.