( CNN ) -- A massive search and rescue mission continued late Friday for nine people who may have plunged into chilly Pacific water off the Southern California coast after a Coast Guard plane and a Marine helicopter collided . `` We 're still in the search and rescue phase . We are not standing down from that at this point , '' Coast Guard Capt . Thomas Farris told reporters at a news conference . `` We have every hope that we 'll be able to find survivors . '' The search will continue , he said , `` Until I stop . '' The Coast Guard plans to continue the search at least throughout Friday night and Saturday morning , Petty Officer Henry Dunphy of the San Diego Coast Guard told CNN . The Coast Guard C-130 plane and its seven crew members had been searching for a missing person when it collided Thursday with the Marine AH-1 Cobra helicopter , with a two-person crew , on a military training exercise , Farris said . None of the names of those on either aircraft has been released . A pilot reported seeing a fireball about 7:10 p.m. Thursday near the crash site . The crash occurred about 16 nautical miles ( 18 miles ) off the coast , near San Clemente Island , said Cpl . Michael Stevens of U.S. Marine Air Station Miramar in San Diego . Helicopters , cutters and patrol boats , aided by the Navy , were scanning a 644-square-mile area for survivors , said Coast Guard Rear Adm. Joseph Castillo . Castillo earlier said an investigation `` to determine what exactly happened '' was beginning . The investigation will be done in `` lockstep '' with the Marine Corps , he said . A large debris field has been located , and debris has been collected , he said . `` The debris is what you 'd expect , I think , from a midair collision , '' he said . The two Marines on the Marine Corps Base Camp Pendleton chopper were one of four helicopter crews involved in the training exercise , Stevens said . The Coast Guard plane had been on a search mission for a couple of days before Thursday 's crash . `` They were searching for a possible person in the water who was reported to have gotten in a dinghy and attempted to row to Catalina [ Island ] , '' Farris said . `` We were searching in that area because of the drift that would have naturally occurred after that event . '' With water temperatures in the 60s , Farris earlier Friday estimated survivability could be up to 20 hours . The missing person the Coast Guard members were searching for prior to the collision is still missing , Farris said . CNN 's Sonya Hamasaki and Larry Shaughnessy contributed to this report .
NEW : Coast Guard Capt . Thomas Farris : `` We 're still in the search and rescue phase '' A Coast Guard plane and a Marine helicopter collided off cost of Southern California . Seven people were aboard C-130 Thursday , which was searching for a missing person . The Marine helicopter contained two crew members .