Officials today imposed extraordinary security at California airports and temporarily held air mail to and from the state after the Unabomber threatened to blow up an airliner leaving Los Angeles International Airport in the next six days.
However, at the end of a day of statewide confusion in air travel and mail delivery, senior law enforcement officials said that a letter had been sent by the Unabomber to the New York Times claiming that the initial threat was a hoax. The Times published portions of the letter in its Thursday editions that said the threat was "one last prank." A senior law enforcement official confirmed that the FBI had authenticated the letter to the Times, which the Unabomber had previously asked to publish a lengthy statement expressing his views.
The latest letter, according to the newspaper, said, "Since the public has a short memory, we decided to play one last prank to remind them who we are. But, no, we haven't tried to plant a bomb on an airline (recently)."
The FBI earlier had said laboratory tests confirmed that a mailed threat received Tuesday by the San Francisco Chronicle was sent by the elusive terrorist, whose name stems from postal bomb attacks aimed at officials of universities and airline companies. The letter marked the first time the bomber has threatened a target in advance. Senior federal law enforcement sources said they believe the recent increase in activity by the Unabomber may have been motivated by the April 19 Oklahoma City bombing.
"The Oklahoma bombing seemed to tweak him. It was almost like, Hey, guys. Oklahoma City may have been the biggest bomb, but I'm still here and you can't catch me,' " one federal official said. Another said that by mailing a bomb threat so close to the July 4 holiday, the Unabomber "seems to be saying, Look at the power I wield.' "
The threat caused delays of flights and long lines at the Los Angeles airport as ticket agents checked passengers for photo identification. Security officials handed out warnings asking the public to be alert to suspicious bags, parcels and other items and to expect delays "as a result of . . . increased security." American and United Airlines waived re-ticketing fees for passengers seeking to change flights.
The threat, contained in a brief letter sent to the Chronicle, was published today. It read: "WARNING. The terrorist group FC, called Unabomber by the FBI, is planning to blow up an airliner out of Los Angeles International Airport some time during the next six days. To prove that the writer of this letter knows something about FC, the first two digits of their identifying number are 55."
The FBI has previously said the Unabomber's identifying number is the same as a Social Security number issued to a Northern California resident who has been cleared of involvement with the attacks.
At first, investigators expressed skepticism about the letter's authenticity, noting many Social Security numbers issued in Northern California begin with the numbers 55. But FBI agent Jim Freeman told a news conference he is "100 percent" certain the letter came from the Unabomber after laboratory tests that he declined to describe were performed.
The "FC" in the letter refers to an anarchistic, anti-technology organization cited by the Unabomber in previous letters but which, according to law enforcement sources, probably does not exist. FBI officials have said they believe the Unabomber operates alone, and that the "FC" designation, which has been engraved in metal components of some of the bombs, has been used to mislead investigators.
Since 1978, the Unabomber has killed three people and injured 23 with 16 bombs. In 1979, 12 people suffered smoke inhalation when an altitude-triggered incendiary bomb exploded in the cargo hold of an American Airlines plane en route from Chicago to Washington. The Unabomber is believed by the FBI to live in the Sacramento or Oakland areas, where some of the explosive devices have been postmarked.
The most recent Unabomber victim was timber industry lobbyist Gilbert Murray, killed in his Sacramento office April 24. In a letter to the New York Times, mailed from Oakland four days earlier, the bomber railed against industrial society and the scientists who support it and offered to stop the attacks if major media outlets published a lengthy manifesto.
The letter to the Chronicle also reflected the Unabomber's apparent fixation on wood -- it had a return address of "Frederick Benjamin Isaac Wood, 549 Wood Street, Woodlake, CA, 93286." There is a town named Woodlake in central California.
The Federal Aviation Administration said security measures "will remain in effect as long as they are deemed necessary." Postal authorities tonight said airlines would accept mail under strict guidelines worked out with the FAA.
At the Los Angeles airport, many passengers took the stepped-up security in stride. "You can't let things like this interfere. You cannot give the people who do this the benefit of {our} anxiety, stress and so forth," said Ralph Briscoe, 65, an employee of an Orange County aerospace company who was flying to Chicago on business. Samantha Mosby, 28, who was flying to Orlando with her husband and 2-year-old daughter, said she was "really scared" by the threat and had thought about canceling her trip. Nonetheless, she said she would board her flight because "I have to go." Special correspondent Kathryn Wexler in Los Angeles and staff writers Pierre Thomas and Don Phillips in Washington contributed to this report. CAPTION: A 1994 artist's sketch of a person believed to be the elusive terrorist, whose bombs have killed 3 people.