"We always hold out some hope, but at this point the Coast Guard has suspended the active search for survivors," Conroy said.
The two aircraft collided Thursday evening as the Coast Guard was searching for a missing boater. The Marine helicopter was flying in formation with another Cobra helicopter and two transports on a nighttime training exercise.
The Coast Guard has begun its investigation into the cause of the crash, Conroy said.
Kenneth Claiborne, the father of one of the missing crew members on the plane, said Sunday that his son, Marine 1st Lt. Thomas Claiborne, had been declared deceased. He declined to comment further and referred calls to a Marine spokesperson.
But the mother of Lt. Adam W. Bryant, 28, from Crewe, Va., who was a co-pilot on the Coast Guard plane, said she hadn't given up hope despite the Coast Guard's announcement.
"Miracles do happen," Nina Bryant said Sunday. "Miracles every day."
Rear Adm. Joseph Castillo said Saturday evening that the chance for finding survivors would be slim, even though the servicemembers had access to heat-retaining drysuits and were in excellent physical shape. Water temperatures were in the low 60s at the time of the collision.
"We don't ever want to suspend the case prematurely, when there may be someone out there," Castillo had said. "But hope gets less every day. My hope today is not what it was yesterday."
The Coast Guard search for the missing boater, David Jines, 50, was called off Saturday evening.
Nine aircraft searched over a 644-square-mile patch of ocean in waters about 2,000 feet deep. Debris from both aircraft was found, but there was no sign of the crew members.
All seven aboard the Coast Guard plane are stationed at the Coast Guard Air Station in Sacramento, Calif. Among the other missing crew members on the plane were Lt. Cmdr. Che Barnes, 35, of Capay, Calif.; Chief Petty Officer John F. Seidman, 43, of Carmichael, Calif.; Petty Officer 2nd Class Carl P. Grigonis, 35, of Mayfield Heights, Ohio; Petty Officer 2nd Class Monica L. Beacham, 29, of Decaturville, Tenn.; Petty Officer 2nd Class Jason S. Moletzsky, 26, of Norristown, Pa., and Petty Officer 3rd Class Danny R. Kreder II, 22, of Elm Mott, Texas.
Maj. Samuel Leigh, 35, of Belgrade, Maine, was the other crew member on board the Marine Corps helicopter.
The investigation will be conducted jointly by the Coast Guard and the Marine Corps, Petty Officer Henry Dunphy said Sunday. The Federal Aviation Administration and the National Transportation Safety Board will be available in a support role, Dunphy said.
The accident happened in airspace uncontrolled by the FAA and inside a so-called military warning area, which is at times open to civilian aircraft and at times closed for military use, FAA spokesman Ian Gregor said. He did not know the status of the airspace at the time of the crash.
Minutes before the collision, the FAA told the C-130 pilot to begin communicating with military controllers at Naval Air Station North Island in San Diego Bay, but it was not known if the pilot did so, Gregor said.
On Saturday, a top Coast Guard official said he believed the C-130 pilot had spoken with the military controllers before the accident.
Accident investigators who began arriving in San Diego on Saturday would review communications between the pilots and between the pilots and the FAA and military controllers, said Capt. Tom Farris, commander of the Coast Guard's 11th District.
Investigators are also collecting witness statements from those aboard the three other Marine aircraft and will check to see if any distress calls were made.