Thirty years ago the World Trade Center located at the foot of Manhattan was nearing completion. One of its boxy towers, five years in the making, had recently become the tallest building in the world. The other would tie that record when it was finished two years later.

I was 19 and a freshman in college when they broke ground on the World Trade Center in August 1966. I was 25 and launching my third career—this one in radio—when it was finished in April 1973. I was also married and a father. That whole time I took a keen interest in the project.

I grew up in New Jersey, across the river from Manhattan. My father grew up there too, in a house atop the Palisades, in Fort Lee. As a young man he was a high-steel construction worker, helping build the George Washington Bridge. We both followed the progress of the World Trade Center and talked about it often, since we shared the same erector-set mentality and love of heights.

For a while I also shared a yard with a British chap named Roy who worked as a foreman on the World Trade Center project. We'd often sit outside drinking Bass Ale while Roy clued me in to the building's highly unusual construction.

With most high-rise buildings, Roy explained, the exterior is cosmetic. It's just fascia. But with the World Trade Center, the exterior was structural. The floors inside were like shelves in a metal box, each held up by tabs and bolts.

I thought about that as I watched the North Tower burn like a giant chimney on live television. By then all we knew was that an American Airlines 767 had flown squarely into the building, filling the upper floors with thousands of tons of wreckage and burning jet fuel.

Like millions of others watching the same coverage, I was filled with dread. Somewhere in there is somebody I know. I also wondered if the structure would hold. The surviving concrete could take the heat, but what about the steel frame? Then came news that another jet had plowed into the Pentagon, and fear became terror. Moments later a third jet flew into the South Tower, disappearing intact, like a knife slicing into a cake. A second after it vanished an orange fireball blasted holes out two other sides of the building. Horrified, I asked myself an awful question: how long before the shell melts and the floors start dropping?

The answer came soon enough. About 15 minutes after absorbing a United 767, the South Tower—the second one hit—sagged into a cloud of gray dust. A few minutes later the North Tower followed. In less than an hour, the world's most important skyscrapers were reduced to a mound of debris and a grave for thousands.

“Who did we know who might be in there?” I wondered. Then I remembered David Alper.

The last time I had seen Dave—whose fortuitous nickname is Save—was back in January at LinuxWorld Expo. (That's him in the picture, getting a slap on the back from yours truly.)

Dave is as New Yawk as they come. Big, generous and full of life, it was hard to imagine the world without him. But I knew he worked in the World Trade Center. Was he at work? Was his office on a high floor? Did he get out?

For days calls to Dave and his wife Susan reached only busy signals or voicemail boxes. But finally, we got a call. Sure enough, Save had earned his nickname, big time.

Turns out he was in his office on the 84th floor of the South Tower when the North Tower was hit. Nobody knew for sure what had happened, but clearly it wasn't good. Ignoring the public address voice assuring people that the South Tower was safe, Dave joined the crowds who started down the stairs. It took an hour to reach the street. While he was still in the stairwell, the second plane tore through Dave's office and pretty much everything else on the floors running from 82 through 85. The building shook but stood. For another fifteen minutes it performed a final service to thousands pouring down the stairs from floors below the impact. Dave was two blocks away when the building fell. From his floor alone more than 70 people were killed.

Nearly a week would pass before my other New York friends, including several who worked in the shadow of the towers, wrote or called to announce their survival. The only casualty I knew personally was Daniel Lewin, the cofounder and CTO of Akamai, which uses Linux and Apache servers to make the Web more efficient for its customers (one of which is Microsoft). Danny was born in Denver but raised in Israel. He was a passenger on one of the planes that crashed into the WTC. If he had known the hijackers' true intentions, I am sure he would have been a hero.

Still, Akamai's technology carried much of the redistributed load when the loss of the World Trade Center echoed through the Internet. Across its native internet habitat, the Linux community has taken to heart the business half of the Slashdot slogan: Stuff that matters. Quietly, with no publicity, enormous rebuilding work is already being done.

As I write this, the event is still only a few days past. It's almost impossible to think, much less write, about anything else. Nothing matters more.

Airplanes have barely resumed flying, but I took one yesterday. It was nearly empty, so I spent the whole flight talking with the flight attendants. One of them described September 11 not as an “Attack on America” (the consensus name given by the major media), but as a “heart attack”. Everything stopped and the country shut down cold. How long, she wondered, could vital economic organs withstand the absence of business travel and freight transportation?

Right now the only thing that's clear is there's a new kind of war going on.

“Compared to war, all other forms of human endeavor shrink to insignificance”, George Patton famously said. No wonder, given the enormous loss of life and property, that our government immediately declared the attack an “act of war”--even though the enemy was an -ism rather than a country.

That enemy seeks to raze in minutes what civilization takes years to raise. Only a few months before terrorists destroyed the World Trade Center, the terror-supporting Taliban government in Afghanistan used enormous ancient Buddhist statues for target practice. How can they possibly succeed at anything that doesn't involve suicide? Especially against the better nature of the species? Of which, both Linux and UNIX are excellent examples.

We've been at work on Linux for more than ten years. Before that we worked on UNIX for decades. This work has had a profoundly civilizing effect on all forms of human endeavor that rely on computing and communications. Without UNIX, the Internet would have been an impossible dream. Now it's an unstoppable reality. Linux makes it more unstoppable every day.

And the more we have to rebuild, the more apparent that will become.