Story highlights

"We are still searching for survivors," official says

The search extends eight miles out to sea from Oahu's North Shore

Surfers and those along coast are warned about possible debris

CNN  — 

(CNN) – Rescuers expanded their search Saturday for 12 Marines missing since their two military helicopters apparently collided in the waters off the Hawaiian island of Oahu.

A Navy ship equipped with sonar arrived Sunday and conducted an underwater search. No additional debris was sighted. Searchers overlapped each others’ areas to provide multiple perspectives and put fresh eyes on them.

It warned people along the coast to alert the Marines if they find any debris along the coast. The area is a popular surfing destination and surfers were told to avoid any debris in the water.

A Marine Corps CH-53E Super Stallion

The Coast Guard, Navy and Honolulu emergency services have conducted some two dozen searches covering more than 5,700 square miles, the Coast Guard said, but so far they have turned up no sign of the missing Marines.

When asked about the possibility of a laser having played a role in the apparent crash, Jenkins said answering at this point would be speculative. The focus right now, he said, is on the search-and-rescue effort.

“We are still searching for survivors. That’s an important point to make,” he told reporters.

Apparent collision

The two CH-53 copters appear to have gone down during a training flight off the Hawaii island of Oahu late Thursday, authorities said. No mayday call was received, just word that something had gone wrong, said Coast Guard spokesman Lt. Scott Carr said.

A civilian on the beach first told authorities of seeing a fireball, followed by a second person reporting a flare.

Searchers spotted a fire and debris field, including an empty life raft, about 2 1/2 miles north of Haleiwa Beach and later floating pieces of debris consistent with military aircraft.

Six people were on board each of the two heavy-lift transport helicopters. Loved ones have identified to CNN four Marines missing, and CNN affiliates have reported on a fifth.

Corps names Marines

The Marine Corps has named the 12 missing men. Base Hawaii named them as:

Maj. Shawn M. Campbell, 41, College Station, Texas

Capt. Brian T. Kennedy, 31, Philadelphia

Capt. Kevin T. Roche, 30, St. Louis

Capt. Steven R. Torbert, 29, Florence, Alabama

Sgt. Dillon J. Semolina, 24, Chaska, Minnesota

Sgt. Adam C. Schoeller, 25, Gardners, Pennsylvania

Sgt. Jeffrey A. Sempler, 22, Woodruff, South Carolina

Sgt. William J. Turner, 25, Florala, Alabama

Cpl. Matthew R. Drown, 23, Spring, Texas

Cpl. Thomas J. Jardas, 22, Fort Myers, Florida

Cpl. Christopher J. Orlando, 23, Hingham, Massachusetts

Lance Cpl. Ty L. Hart, 21, Aumsville, Oregon

“Our thoughts and prayers are with the Marines and their families as we continue search and rescue efforts,” Base Hawaii said.

Reported missing

Schoeller’s family released a statement. “We value all of the thoughts and prayers offered up on our behalf during this very difficult time.”

USMC Corporal Christopher Orlando

The family of Cpl. Christopher Orlando, 23, of Hingham, Massachusetts, said he was aboard one of the helicopters.

The family of Captain Kevin Roche told CNN that he is among the 12 Marines missing in the Hawaii helicopters collision.

Anthony Kuenzel of Missouri told CNN that his brother-in-law, Capt. Kevin Roche, is among them. The family described him as a passionate Marine and thanked people praying for him.

Loved ones have reported Maj. Shawn Campbell and Cpl. Matthew Drown missing after the Hawaii helicopter crash.

Maj. Shawn Campbell, 41 was in the collision, said his mother, Donna McGrew, of Houston. A Marine officer visited her at home to brief her. Campbell has a wife and four children, and has done three tours of duty in the Middle East.

“My heart just breaks, there are 11 other families going through this now. God bless them,” McGrew said.

CNN’s Melissa Gray, Dana Ford, Dave Alsup, Barbara Starr and Joe Sutton contributed to this report.