SAN DIEGO (AP) — The U.S. Coast Guard and Navy were still hoping Friday to find survivors of a collision between a Coast Guard plane carrying seven people and a Marine Corps helicopter carrying two off the Southern California coast.

The crash was reported at 7:10 p.m. Thursday, about 50 miles off the San Diego County coast and 15 miles east of San Clemente Island, Coast Guard spokeswoman Petty Officer Allyson Conroy said.

A pilot reported seeing a fireball near where the aircraft collided, Federal Aviation Administration spokesman Ian Gregor said, and the Coast Guard informed the FAA that debris from a C-130 had been spotted. The Coast Guard plane that crashed was a C-130.

The Coast Guard crew members had survival gear onboard their aircraft, including exposure suits that could have allowed them to survive in the water for hours, Petty Officer Henry Dunphy said Friday from San Diego.

“We’re hoping to find survivors,” he said. “We’re not ruling that out.”

At least seven Coast Guard and Navy ships and several helicopters continued a search that ran overnight under a bright moon in calm seas.

“We’ve pretty much thrown everything we have at it right now,” Dunphy said.

The Coast Guard plane was based in Sacramento and was on a search-and-rescue mission when the collision occurred, Dunphy said. He did not have details of the mission.

The AH-1W Super Cobra helicopter was on a training mission when it went down, said Cpl. Michael Stevens, a spokesman for the Miramar Marine Corps Air Station.

The Cobra and its crew are part of Marine Aircraft Group 39, based at Camp Pendleton, and the 3rd Marine Aircraft Wing, which is headquartered at Miramar, Stevens said.

San Clemente Island is the southernmost of the eight Channel Islands located 68 nautical miles west of San Diego. The Navy has owned and trained at San Clemente Island since 1934, according to the island’s Web site. Naval Air Station, North Island is responsible for the island’s administration.

Earlier this week, it was an AH-1 Cobra attack helicopter that collided with a UH-1 helicopter over southern Afghanistan, killing four American troops and wounding two more, a Marine spokesman said.