Unidentified flying discs. Secret military missions. Government cover-ups.

The story Philip Lipson and Charlette LeFevre have been researching for years has almost all the elements of a made-for-TV movie.

As the story goes, a government employee swore he saw flying saucers three days after a Tacoma man said similar UFOs spewed metal and lava onto his boat. There was even a man in black.

A witness later recanted his statement - some say out of fear - after a military plane supposedly transporting classified debris exploded into flames.

"You don't want to know how complicated and bizarre this is," said LeFevre, who, with Lipson, runs the Seattle Museum of the Mysteries on Capitol Hill.

Lipson and LeFevre believe that 60 years ago a plane that crashed in Kelso contained slag from a UFO. They've tracked down newspaper stories and testimony, and gathered the clues at their museum.

But it's the black chunk of rock they keep locked in a glass case that may be their best clue, and a scientist may test the rock this week.

Officially, the story is poppycock. The government dismissed it as such decades ago.

Damaging debris

On June 21, 1947, Harold Dahl was salvaging logs near the shore of Maury Island. Dahl said that at 2 p.m. he saw six doughnut-shaped aircraft, about 100 feet in diameter.

He said five of the metallic aircraft, which didn't appear to have signs of propulsion, circled above one, which dropped to about 500 feet and spewed what he thought was 20 tons of metal and molten rock.

Dahl reported to co-worker Fred Crisman that the falling debris injured his 15-year-old son, killed their dog and damaged the boat's wheelhouse.

Three days later, U.S. Forest Service employee Kenneth Arnold said he saw nine similar flying saucers between Mount Rainier and Mount Adams. The Associated Press published Arnold's claims that when one of the aircraft dipped, the others did, too.

The day after Dahl's sighting, a man in a black suit arrived at his Tacoma home in a black 1947 Buick, Dahl said later. Books by UFO historians say the man in black threatened Dahl, saying that if he cared about his family, he'd never speak of the incident again.

He spoke of it at least one more time in July 1947, when he met with Arnold in a secret meeting in Room 502 of Tacoma's Winthrop Hotel. Arnold wrote about the meeting in his 1952 book, and said they were also joined by United Airlines pilot Capt. E.J. Smith - another who claimed to see the discs - as well as Air Force Lt. Frank M. Brown and Capt. William L. Davidson.

Smith told The Idaho Statesman that Brown and Davidson were given six pieces of "metal or lava."

The chunks were loaded onto a B-25 bomber at McChord Field to be shipped to a California military base, according to the now-defunct Tacoma Times.

B-25 crash

It was still dark in the early morning of Aug. 1, 1947, when a fire erupted in the left engine of the B-25.

Longview police officers reported watching the B-25 circle over Longview and Kelso, leaving a streak of smoke behind the burning motor.

When attempts to extinguish the fire failed, two other crew members - Sgt. Elmer L. Taft and Tech. Sgt. Woodrow D. Matthews - parachuted to safety. Brown and Davidson, who some believe knew there were UFO parts on the plane, stayed with the bomber.

The B-25 crashed into the base of three alder trees. Brown and Davidson's mangled bodies were thrown clear.

On Aug. 3, 1947, an Associated Press report said the men died investigating flying saucers.

Black chunk

Kelso resident James Greear heard about the crash 10 years ago and had made several attempts to find clues. He found almost nothing in the woods until earlier this month, when Bob Davenport told him the exact location. Davenport, now 75, was 15 at the time of the crash and one of the first people to rush to the wreckage.

Greear went to the crash site April 15 with Lipson and LeFevre.

In the north fork of Globe Creek, a friend of Greear's found a black chunk slightly larger than a softball that looks as if it could have once been lava.

"We are not making any claims of what it is," Lipson said.

But he and LeFevre are hopeful.

"You can tell it's been liquid because it's all full of bubbles," said Bill Beaty, a research engineer in the University of Washington's Chemistry Department. He plans to have a colleague analyze the chunk this week.

"We have to look at the bedrock in the hill and see what's there," he said. "If it looks like that, then it's probably the same.

"If this is totally different than the bedrock that's there, then this will be very interesting."

Rarely spoke of sighting

Though popular among conspiracy theorists, Dahl's claim that a UFO spewed debris onto his boat is likely to remain folklore.

"I didn't know anything about it until 2003 when a man from Sacramento sent me about 50 pages of research about it," said Dahl's 76-year-old daughter, Louise Bakotich of Aberdeen. Though Arnold insisted his sighting was real, Dahl rarely spoke of his sighting after 1947, and often said it was a hoax when he did. Charles Dahl, who was supposedly injured by the falling debris, didn't confirm the injuries before his death, his sister said.

The Army and Air Force have repeatedly denied that UFO fragments were on the B-25 flight. An August 1947 document, said to be from FBI Director J. Edgar Hoover, states that the story of the B-25 having flying disc fragments was a hoax.

Those statements, however, only fuel the curiosity of UFO researchers such as Lipson and LeFevre.

"We're starting where they left off 60 years ago," LeFevre said. "There's a lot more out there."

P-I news researcher Marsha Milroy and P-I librarian Lytton Smith contributed to this story.

P-I reporter Casey McNerthney can be reached at 206-448-8220

or caseymcnerthney@seattlepi.com.

SEE THE B-25 CRASH ARTIFACTS

Seattle Museum of the Mysteries is at 623 Broadway Ave. E. General admission is a $3 suggested donation. Children 15 and younger are free. Hours vary. Large groups are asked to call ahead: 206-328-6499. The museum's Web site is here

FBI documents relating to the Dahl sighting: goto.seattlepi.com/r687

The Strange Summer Of 1947

June 21: Harold Dahl says he saw six doughnut-shaped aircraft, about 100 feet in diameter.

June 24: U.S. Forest Service employee Kenneth Arnold says he saw nine similar flying saucers south of Mount Rainier.

August 1: A B-25 airplane leaves McChord Field in Tacoma and crashes near Kelso. A United Airlines captain says that "metal or lava" associated with the mystery flying objects was on board.