By Jorene Barut

HONOLULU (Reuters) - Some 120 aging survivors of the attack on Pearl Harbor were among 5,000 people who marked its 70th anniversary on Wednesday with a quiet, often emotional ceremony at water's edge.

With a light rain falling, speakers remembered those killed or wounded seven decades ago as well as survivors who fought in World War Two following the Japanese air and naval assault on December 7, 1941.

"We gather here today to commemorate the 70th anniversary of one of the most significant events of the 20th century," 88-year-old veteran and Pearl Harbor survivor Mal Middlesworth said in a keynote address.

"We do this best by honoring all who gave their lives on all the military bases on the island of Oahu that Sunday, not just Pearl Harbor," said Middlesworth, who was an 18-year-old Marine serving on the USS San Francisco that morning.

As though to underscore the historical distance, however, members of the Pearl Harbor Survivors Association, made up of 2,700 veterans who were within three miles of Pearl Harbor at the time of the raid, announced that they would disband due to the age and failing health of its dwindling number of members.

Middlesworth, a past president of the Association, said the veterans "wanted young America to understand that freedom isn't free. It never has been and it looks like it's never going to be."

He added: "Let no author, historian or politician attempt to rewrite the history of what happened here 70 years ago. Let no one disturb the sacred water in the harbor."

Organizers said the 5,000 people attending the ceremony marked the largest turnout since 1991, the 50th anniversary of the attack.

The event opened with a Hawaiian blessing and prayer, followed by four F-22 fighter jets flying over in a missing man formation.

Edward Wentzlaff, who was a 24-year-old chief warrant officer on the battleship USS Arizona on the morning of the raid, traveled from Minnesota for the ceremony and vividly recalled the events of 70 years earlier.

Wentzlaff, now 94, said he had been preparing for a church service when he heard a loud boom and saw an aircraft strafe one side of the ship as a torpedo hit the other.

"The smell of burning flesh has a sickening odor that stays with you; it's upsetting," he said.

Nearly half of those who perished in the attack on Pearl Harbor were sailors aboard the Arizona, which Japanese torpedo bombers sank early in the attack, sending 1,177 of its 1,400-member crew to their deaths.

The USS Arizona Memorial, built over the remains of the ship, now forms a centerpiece of the World War Two Valor in the Pacific National Monument, an historic site administered by the National Park Service.

Besides the nearly 2,400 who were killed, the attack left 1,178 people wounded, sank or heavily damaged a dozen U.S. warships and destroyed 323 aircraft, badly crippling the Pacific fleet.

(Writing by Dan Whitcomb. Editing by Peter Bohan)