New evidence indicating the Japanese attacked Pearl Harbor effectively from under water, as well as the air, was announced today by the “;NOVA”; television series on the anniversary of the 1941 attack that led the United States into World War II.

“;Pearl Harbor was always seen as an aerial attack,”; said Parks Stephenson, lead investigator of an underwater expedition for the PBS science series, which explored the wreckage of a midget submarine discovered by University of Hawaii researchers.

Eyewitness accounts, a congressional report by Adm. Chester Nimitz, former Pacific Fleet commander, and other clues indicate the midget sub fired two torpedoes and claimed success in a radio call to the Japanese high command 12 hours after the attack, he said.

Stephenson said the accounts indicate one torpedo was fired at the USS Arizona that was a dud, but he believes another torpedo hit the USS Oklahoma.

The marine forensic historian and former U.S. Navy officer and submariner discussed the findings of the expedition in a telephone interview from his San Diego home. “;NOVA”; will present the new evidence and underwater footage of the Japanese midget submarine in a TV documentary, “;Killer Subs in Pearl Harbor,”; premiering on KHET-PBS Jan. 5.

“;A giant piece of the Pearl Harbor puzzle has fallen into place,”; Stephenson said. “;This important discovery sheds light on a World War II mystery that has eluded historians for nearly seven decades.”;

Five Japanese “;mother”; submarines approached within a few miles of Pearl Harbor before the Dec. 7 battle, each carrying a Type-A, two-man, midget submarine, about 80 feet long and 6 feet wide, NOVA said.

The sophisticated midget subs were twice as fast as many U.S. subs of the times, with 600-horsepower electric motors that could propel them underwater at speeds of 19 knots (22 mph). They were capable of carrying two Type 97 Long Lance Torpedoes.

All but one of the five midget submarines were found over the years, “;either destroyed, scuttled or run aground,”; NOVA said. “;They missed the targets, failed to fire or were recovered with torpedoes intact. But historians have long puzzled over the fate of the missing sub.”;

Stephenson, a Lockheed Martin engineer, said the submersibles Pisces IV and Pisces V, belonging to the Hawaii Undersea Research Laboratory, found three sections of the missing sub in cruises over the past few years in the same area south of Pearl Harbor.

He accompanied Terry Kerby, HURL operations director and chief pilot, on a “;validation”; cruise in March. Kerby had been the first to spot the midget sub amid damaged equipment and landing craft from the 1944 West Loch explosion.

Also along as observers on the UH submersibles in March were a Japanese expert on midget subs and retired Adm. Kazuo Uyeda, the senior surviving midget submariner from WWII.

“;One can conclude definitely that this was the special submarine that was used in Pearl Harbor,”; Uyeda said.

Stephenson said microbiologist Lori Johnston, who did extensive work on the Titanic, sunk in 1912, determined the torpedoes were fired before the sub sank because of rustlike encrustation covering the empty torpedo tubes.

A survivor of the Oklahoma described one torpedo as much more violent than others hitting the ship, he said.

“;So the Oklahoma, in my eyes, is the leading candidate”; for the midget submarine's torpedo. “;I have a theory that if the Oklahoma had not been hit by a more powerful torpedo, it might have righted itself like the West Virginia.”;

As more evidence, a photo taken by a Japanese airplane during the attack seems to show the conning tower of the midget sub at the surface pointed at the Oklahoma, Stephenson said.

Nimitz described an unexploded torpedo sighted and recovered inside the harbor with an explosive charge of 1,000 pounds—more than twice that of aerial torpedoes—which provides “;corroborating evidence that a midget sub did penetrate Battleship Row and fired upon it,”; said “;NOVA.”;

U.S. veterans told “;NOVA”; investigators the Arizona was torpedoed from below, but “;NOVA”; divers who had special permission to film the hull 40 feet beneath the surface found no visible signs of a torpedo hit.

It is believed the midget sub escaped to a secluded area of West Loch, remained undetected to get off a radio call, then was scuttled by the crew to keep it out of enemy hands, Stephenson said. The fate of the crew is uncertain.

Why it was found in three sections on the ocean bottom several miles outside of Pearl Harbor was a puzzle until “;top secret”; information was revealed recently about an ammunition explosion that killed nearly 200 sailors and wounded hundreds more in West Loch on May 21, 1944, “;NOVA”; said.

“;The U.S. Navy quickly and quietly cleaned up the remnants of the 1944 West Loch disaster to get the top-secret (Guam, Saipan and Tinian) invasion back on track.”;

Stephenson said he believes the Navy found the midget sub and took it with the rest of the debris a few miles outside of the harbor and dumped it all together.

Burl Burlingame, a Star-Bulletin writer, author of “;Advance Force Pearl Harbor”; and a historian for the “;NOVA”; project, said, “;The more we learn, the more mysterious it gets.”;