Tokyo -- It was a beautiful spring morning outside as the rush-hour trains pulled into their downtown subway stations. But when the commuters spilled out onto the platforms, it was clear that something was horribly wrong.
Many collapsed in spasms. Others rubbed their failing eyes, or coughed and retched uncontrollably. More than 5,000 were sickened and a dozen would die -- most without knowing they were the victim of a terrorist attack.
Last month's attacks on the United States have elicited an eerie sense of familiarity in Japan. Six years ago, a well-trained team of religious fanatics fanned out across Tokyo's subway system, puncturing bags of homemade nerve gas and deeply shaking this country's sense of security.
But for those seeking lessons in how to protect a city from terrorists, Tokyo's example isn't very encouraging.
Experts say that although Japan has largely crushed the cult responsible for the 1995 subway nerve gassing, its cities are as vulnerable today as they were then. And, they fear, the one true lesson may be that there simply is no practical defence against terrorism.
"There is no safe place in Japanese cities," said Tadasu Kumagai, a well-known private military analyst. "After about two months, people stopped seriously discussing what to do if and when another attack were to occur."
Following the March 20, 1995, gassing, officials here did pretty much what President George W. Bush is doing now.
Within days, investigators had publicly identified as their prime suspect Aum Shinri Kyo, a neo-Buddhist doomsday cult known for its militant, Armageddon-laced rhetoric. Leaders were rounded up and jailed, facilities were shut down and tons of chemicals confiscated.
Riot police were deployed around potential targets, large public gatherings were cancelled.
In the subways, coin lockers were shut down, garbage cans were removed or covered up and announcements urging passengers to watch out for unaccompanied bags became a part of the daily routine.
Japanese officials also focused on the longer-term goals of improving their intelligence-gathering abilities and passing laws to restrict Aum's ability to raise funds and solicit new members. On that front, they found some success.
The cult still exists, but is much weaker. Though its activities are closely monitored, it is not considered a serious threat. Its founder, Shoko Asahara, is being tried for murder, and most of its other senior members are either dead, on trial or serving long prison terms.
But concerns over civil rights forced officials to back away from many of the bills they had sought. And questions remain over whether the police, now mired in unrelated bribery and misconduct scandals, have the focus to apply the lessons of Aum should a new terrorist threat arise.
Public security, meanwhile, has for the most part reverted back to what it was before the attack.
Ryuichi Kinoshita, a spokesman for the Teito Rapid Transit Authority, which operates several Tokyo subways, said there are more surveillance cameras in the underground and subway workers conduct daily checks for suspicious objects.
That's about it.
Metal detectors or other more intensive searches were never introduced. The cautionary announcements ended years ago.
"We can't rule out the possibility that the same kind of incident will happen again," Kinoshita said. "In 1995, it just happened to occur in a subway. But there are so many other unguarded places everywhere in Japan where people converge, from department stores to stadiums to parks."
Aum offers other similarities with the terrorist attacks in the U.S.
Just as Osama bin Laden is suspected of having been involved in previous attacks, Japanese police discovered violence linked to Aum had been escalating for years, and that it had killed seven people with nerve gas in 1994.
Police found evidence the cult had attempted to use biological weapons in Tokyo eight times, though they failed to cause infection.
News reports of Aum's various plots generated a boom in sales of gas masks and other survival goods -- just as is now happening in the United States.
But the sales quickly tapered off. People in Tokyo still fear a terrorist attack, but most say are resigned that there is little they can do.
"Even if you buy a mask or something, it's not enough," said Takashi Kasai, a 24-year-old travel agent. "You can't carry it around every day."
And for those who doubt the possibility of a second attack, Japan again offers a bleak precedent. Despite the intense security, less than one month after the subway gassing the nation's top police official was shot four times and seriously injured while on his way to work.
Evidence seized since the attack strongly implicates Aum. But the masked gunman, who escaped on a bicycle, was never caught.