Aside from being awoken by a phone call from Helsinki, September 11th started out like any other day. Allu, a colleague from our office in Finland, was calling to tell me about a problem with some of our servers in London. A customer was demanding that the problem be fixed immediately, and given the precarious nature of our company’s finances, we didn’t have the luxury of being able to piss off customers that other companies might enjoy.

I quickly threw on some clothes, skipped the shower, and began my daily commute by walking the two blocks to the 77th Street subway station. According to my computer’s clock, I arrived in the office at 8:37AM, not much earlier than I would have otherwise, though the minor difference seemed more jarring given the manner in which I was awoken.

Our office, located in Fashion Towers (an undeservedly pretentious name), sits in the heart of the Garment District, midway between Times Square and Madison Square Garden. Like many cash-strapped technology startups, we share our space with another company, in our case, a software consulting firm. Several people were already in the office when I sat down, logged in, and tried to diagnose the problem in London.

John, our CFO, sat in an invisible corner of an office at the other side of the floor. He usually arrived bright and early, leaving his home in New Jersey at 5:00AM. His presence ensured fresh-brewed coffee, for which I was always thankful. John shared the room with Mike, the CEO, and Brian, the President, both of whom had also just arrived. Chua, an engineer with the consulting company, sat at his desk in the row next to mine, exchanging instant messages with Vic, a friend who works in lower Manhattan.

As was our morning ritual, Chua and I traded a few remarks about baseball while I scanned my morning e-mail. There was nothing urgent to read, so I connected to the servers in London and tried to diagnose the problem. I checked our system’s code, file permissions, account names and passwords, losing myself in the problem, but nothing seemed out of the ordinary until a rather loud “Holy Shit!” came from Chua.

An explosion ripped through the top of one of the World Trade Center towers, and Vic saw it from his window at work. 1993 all over again, I thought. Our office has no TV or radio, so Vic was our news media. He supplied us with updates from the TVs that hung from the ceiling above him: what he assumed was a bomb turned out to be a small plane. An accident, surely. Then the small plane became a passenger plane. I called my girlfriend Elizabeth to relay the news, and when she turned on the TV, she saw the second plane hit. Two planes, one into each tower; this was obviously no accident.

I put down the phone and shouted the news to my officemates. Everyone gathered in the main room and stood around stunned, muttering various phrases of disbelief. Several of us went out to the fire escape, to see if anything was visible from the roof. We walked up one flight and saw a vertical service ladder to the next level. We climbed it, found another, and climbed once more. On the roof, we could see both towers pouring smoke, the smoke swept by the wind towards Brooklyn. The crackling roar of a plane streaked overhead—it was a much different sound from a passenger plane—and we looked up to see an F-14 fighter patrolling the skies of New York.

Across 7th Avenue, we saw dozens of people on the roof of another office building. I looked around, and almost every roof that could be seen was hosting more and more people. Everything seemed in slow motion up there on the roof; the smoke drifted upward and eastward slowly, the fire seemed to be a stationary bright orange glow. We knew we were witnessing something horrific, but we had no idea how historic it would become. Nor did we realize that our city was about to become permanently disfigured.

I went downstairs to call a few people and see what they’d heard. My mom and Elizabeth both pleaded with me to leave the building. Being a few blocks from another symbol of New York—Times Square—wasn’t safe, they said, and they were right. But the reality of what happened had not yet set in, so it was easily overruled by the reality of working for a company that’s been on the brink of collapse for months. One angry customer in Helsinki very well might end up scuttling our pending bridge loan. No bridge loan, no job. Not for me, not for anyone. I felt as though the fate of company fell on my shoulders.

Working a bit more on the problem, I decided to leave the minute it was fixed, thinking it could be fixed soon. The phone rang; it was Allu in Finland. He was calling to ask the status of the problem, I assumed. The network had slowed considerably, and I kept getting kicked off the servers in London. But Allu wasn’t interested in any of that. Instead, he had news. I yelled out each item as he reported it: The Pentagon was struck by a helicopter and was on fire. The Mall in Washington was on fire. The West Wing of the White House had been struck. There were still hijacked planes in the air. The prime suspect: Arab terrorist Osama bin Laden.

I got off the phone, feeling as though I’d gotten the wind knocked out of me. What the hell was happening? Were we at war? Too fidgety to sit, I didn’t know what to do, so I went to the kitchen to look out the window and make sure that the Empire State Building was still there. I stood staring at the building, wondering if a plane would hit it next. Looking out the window, everything seemed so vivid. The sun was bright, the sky clear, and from up where I was, the city seemed peaceful.

It was the clarity of a dull shock setting in; something huge was happening, but nobody knew what it was. While I stood staring out the window, people in the next room shouted new information: The White House was not hit. A plane buzzed the Capitol Dome. The Mall was not on fire. The Pentagon was hit by a plane, not a helicopter. The line between fact and rumor was fluid, so aside from what we could see from the roof, we were skeptical of everything; yet, because of what we could see from the roof, everything seemed plausible.

Back in the main room, Chua reported another message from Vic: one of the towers had collapsed. I ran back up the fire escape and climbed the ladders to see for myself. Too much smoke obscured the view, so it was difficult to tell; even the people who had been on the roof weren’t sure, but were fairly convinced that a tower did collapse. For a second, the wind broke the smoke, laying to rest all doubt: only one tower remained.

I ran back downstairs to get my things and get out. The more I saw and heard, the more obvious it became that midtown Manhattan was probably not the safest place in the world to be. If there were more strikes planned, our area was a likely next target. I gathered my work and my laptop, hurriedly stuffed them into my bag, and tried to understand the magnitude of what was occurring.

David, our Vice President of Engineering, came down from the roof and said the second tower had just collapsed. He agreed that it was time to go. But we still had our problem to fix, so David and I decided to go to his apartment and finish the work. We rode the elevator downstairs, stepped out onto Seventh Avenue, and tried calling friends and relatives to tell them that we were safe, but cell phones were virtually useless; only one in twenty tries resulted in a call.

It seemed that every office building in Manhattan was being evacuated. At street level, there were so many people scurrying in every direction that it was impossible to avoid bumping into someone every few seconds. The sidewalks were so packed, people took over the streets as well. The subways, our normal ride home, were shut down. Empty taxis were nowhere to be found. Buses were squeezed full; there was no hope of getting on, which didn’t matter anyway, since every intersection in Manhattan was gridlocked. We, like the tens of thousands of New Yorkers we tried to avoid bumping into, had no choice but to walk home.

We planned in advance what we assumed would be the safest route for our three-mile walk. We couldn’t go up Seventh because we’d hit Times Square. Sixth was too close to Times Square. Fifth was too much a symbol of wealth. Much further east and we’d be at Grand Central, another possible target. So we chose Madison and started walking east on 37th to get there. At Madison, we headed north.

Along the way, an occasional lone person stood crying, wandering the street broken and in no particular direction. I could only guess who they had lost. Dear friends, close parents, beloved sons and daughters, siblings that seemed like extensions of themselves; these people had just had love ripped from their lives irrevocably. From now on, their lives would always be measured in two parts: the part before September 11th, and everything after. Each time I saw someone crying, I wanted to go over and be of some comfort, but didn’t know how. I walked by with an exhale and tears welling up in my eyes.

At 42nd Street, we overheard a man talking about Grand Central being closed: no trains were going into or out of Manhattan. At 46th, we went east one block to Vanderbilt, where we saw a pickup truck with its door open and the radio tuned to 1010 WINS, a local news station. Several dozen construction workers were gathered around listening, and we stopped to join them. Another plane crashed in rural Pennsylvania. All bridges and tunnels leading into Manhattan were closed. Manhattan was once again a true island for the first time in well over a century.

People talked in a low murmur. Watching people interact during this morning mass exodus, it occurred to me that this was one of those events that made all New Yorkers equal. I’d seen hints of it before, under much more benign circumstances: The 3-foot blizzard that shut down the city for a week. Hugging fellow fans in the Yankee Stadium bleachers when Jim Leyritz hit the 15th-inning homer against Seattle in ‘95.

This had an element of that unity, but it was obviously a much more sinister equalizer. Mailroom clerks, CEOs, cafeteria cooks, stock traders, receptionists; they were all killed. Wealth couldn’t buy a ticket out. Black, white, Asian, Hispanic, Christian, Jew, Hindu, Muslim; the planes and toppling buildings dispensed death without discrimination. I stood there listening to the radio, thinking about the shared experiences that bring New Yorkers together. A sudden hush of the mumbled discussions brought me back out of my head.

I looked up to see two Arab men dressed in Islamic garb walking down the street. They received steely stares from the quieted men whose eyes followed them as they walked by. The looks these Arab men received worried me. I knew they would get that and possibly much worse over the coming days and weeks, and in the wrong place at the wrong time, either one of them might serve as a convenient proxy for Osama bin Laden in some angry eyes.

But they rounded the corner and were gone, and everyone’s attention once again returned to the radio. After we’d heard the same news story twice, it was time to move on. At 47th, we walked east to Park, and once again walked north. At 51st, we found an empty cab. There were now many empty cabs, probably because none of them were moving. But it was hot, so we decided to hop in, cool off in the air conditioning, and listen to more news.

A half-hour later, we found ourselves at 54th and Park, an average of one block every ten minutes. We paid for the cab and got out, feeling like tourists considering the price for that distance, but at least we weren’t sweating anymore, and we gathered from the news that the morning assault on our city and our country had subsided.

We walked east, this time to Second Avenue, and again headed north. The 59th Street Bridge was closed to vehicles, but a wide river of people narrowed to the on-ramp and flowed over the bridge to Queens. Below the Roosevelt Island Tram, five MTA buses sat, lined up and empty, with their drivers outside announcing that they could not leave the borough of Manhattan. Police officers struggled to clear the street as fire engines from the suburbs raced down Second Avenue with sirens blaring, about one every thirty seconds.

At 69th Street, we arrived at David’s apartment with every intention of solving the problem with our servers in London. But first, we turned on the TV to hear the latest and were bombarded with images neither of us will ever forgot.

We saw smoke rising from the black gash sliced into the side of the tower by the first plane. We saw the second plane glide into the tower with no apparent resistance and the explosion it forced out the other side of the building. We saw people jumping from the towers by the dozens, their bodies doing slow cartwheels in the air as they hurtled towards the ground. We heard the screams of the crowd reacting.

We watched a tower buckle at the top and saw the cloud of dust and ash blow out of the point where it crumbled. We saw the huge antenna being dragged down by the top of the tower as it rode the falling building to the ground. We saw the smoke and debris flare out from the tower and rain down on the street. We saw rolling clouds hundreds of feet high burst from the collapse into the streets, chasing down frantic pedestrians.

We saw the ghostly look of people wearing the same sheet of grayish-white ash that all of lower Manhattan wore. We saw them walk out of the haze of dust, zombie-like, some of them with their faces wiped clean, looking like masks against the soot that covered the rest their bodies.

We saw people sitting on curbs, clothes dripping with streaks of blood, while rescue workers stood above, pouring water on their wounds. We saw people crying, holding their trembling hands to their faces in shock as they struggled to squeak out a sound. We saw a seven-story skin of one of the towers atop a five-story pile of rubble.

We saw our magnificent city turned into a war zone. We saw our own people, the guys we stood next to on the subway twice a day, the women on line ahead of us at the bank, the firemen from the station down the street, the cops who protect our neighborhoods, and the ambulance and EMS workers who save our lives daily, we saw these people killed in front of our eyes, with the cameras rolling, live on national TV.

It was impossible to focus on anything other than what we were seeing, so we sat silent and appalled, watching and rewatching the same images, burning them into our memory. We’d forgotten about our little server problem. When we remembered, a half-hour or so of work fixed it. What would otherwise have been the major event in my day was nothing more than a minor distraction, a little irritant, one that kept me from the reality that seemed so close and yet so distant.

That night, I had a fitful sleep. Every so often, I’d wake up, not quite aware yet, and then I’d feel the memory of the day’s events wash over me like warm water. Each time, there would be seconds of consciousness where life as I knew it was exactly the same as it was before the first plane hit. And then memory would creep back. It was the relief of waking up from a nightmare played in reverse.

My dreams that night were all exactly the same: the image of the second plane coming around to hit the tower, and how it tilted to the left just before it hit. It tilts and curves around to hit the tower squarely, as if hitting it on the corner or with only part of the plane would not cause sufficient death.

It’s the tilt that gets to me. There’s a person behind that tilt. A person who decided to die and take thousands of lives with him. There’s a consciousness behind that tilt, one filled with evil, one built of horror, but it’s a consciousness that started life as we all did. So what happened? What went wrong?

I’ve always had a certain faith in every human. I’ve always believed that people at their core were good. And although I believe in God, I’ve never been one to think too much about whether there is a Satan. The concept seems so outmoded, so medieval. But after witnessing Hell on Earth, after seeing the images of evil played out again and again, after breathing the burnt jet-fuel air, after seeing missing persons posters so often that I recognize the names and faces, after realizing that I was now instinctively looking to the sky every time a plane flew by, after living, breathing, dreaming, and seeing nothing but destruction and death, after all these things, how can I be so sure that there is no Satan? How can I be so sure that he didn’t show himself to the world on the morning of Tuesday, September 11th, 2001?