July 7, 2005. I was looking forward to today. Yesterday had ended on a high. London had been nominated as the Olympic City for 2012. I had two excellent assignments today; the first was an 8.30a.m. photo-call at the Natural History Museum to photograph a new diamond exhibition. The second was an exclusive look at how the police were monitoring the security for the G8 summit from their secret control center.

A gentleman makes his way across Edgware Road, still clutching his morning paper after a suicide bomber killed himself on a train at Edgware Road station, one of four terrorist attacks in London. Edmond Terakopian/PA

There must have been around 20 photographers waiting to photograph the world's largest uncut diamond. I was waiting patiently, macro lens and lights in hand, for my turn. As I contemplated getting a coffee, my phone rang; it was the Press Association office, for whom I was working. "There's been an explosion at Aldgate East tube station. Get there. They're saying it's a power surge." I caught everyone's attention as I started to pack away my gear. Slowly, the others began to get calls.

I got in my car with a friend from AP and we started making our way as quickly as traffic allowed. The phone rang, "There's been a second explosion at Edgware Road tube. Go there instead as you're closer." My heart sank. This was no longer an accident as originally thought. How can there be two explosions on the tube in the same morning? I knew it must be terrorism. I began to think of 9/11. The first plane could have been an accident ...

We were very lucky. The traffic was a lot better than usual and we got to Edgware Road quickly. As we got to the scene, we were greeted by silence. The emergency services were all busy. No screaming of orders, or the sound of sirens. Unfortunately for photographers, the police had erected their cordons, and there was no way to get close to the tube station. I did a quick walk around the roads and decided which would be the best. Luckily I had picked the correct road. Within 10 minutes, the first passengers walked out and down the road, closely followed by the walking wounded. The first sight that drew me was a lady being helped by a young man. Her face was burnt and she had a protective white face mask on. She was barefoot, and had blood on her legs.

A lady, covered in soot from the Underground [subway] makes her way to treatment. She was one of the walking wounded leaving the station to be treated at the London Hilton Metropole, a temporary treatment center, on Edgware Road. Edmond Terakopian/PA

For the next five minutes, all I saw was through the viewfinder. I was concentrating on the images that were presenting themselves. My only thoughts were which camera to use for each image (I had three bodies, one with a 300mm, one with a 70-200mm and one with a 24-70). It was a very intense five minutes. So many were injured. The thing that struck me though, was I saw only one person crying. Everyone else was composed; there was no screaming, no running. Everyone, including the lady with the burnt face, and even the crying lady, were very dignified. I saw a gentleman, bandaged on his neck and head, blood on his face and shirt, still carrying his newspaper (now covered in blood) as if nothing out of the ordinary had happened. It was amazing. This embodied the British spirit: the stiff upper lip.

The wounded were taken to the Hilton Metropole Hotel. I decided to sneak inside and managed to stay for several minutes, taking pictures of the wounded waiting for treatment. It must have been the world's poshest triage area. The hotel's security soon noticed me, and I was asked to leave.

Passengers covered in blood and soot make their way to the treatment center after a suicide bomber killed himself on a train at Edgware Road Station, one of four terrorist attacks in London. Edmond Terakopian/PA

After another 10 minutes or so, it was obvious all the pictures to be had were taken and I made my way to the nearest Starbucks to wire on their WiFi. Although all the cell phone networks were down, WiFi was still working. After wiring I returned to the scene. I contacted the office and they asked me to check out Kings Cross station. By now, we knew that there were at least four explosions; three on the tube, and one on a bus.

As I made my way there, a friend contacted me saying that he had heard that someone had been evacuated from Leicester Square tube following another explosion. On arrival I encountered no cars, buses, or people. There hadn't been another terrorist blast. Later I heard that the event had been a controlled explosion of a suspect package by the Army.

I got to Kings Cross. Police cordons were up and there was no access. The explosions were below ground and there was nothing to photograph. Knowing how long this day was going to be, I grabbed a sandwich and a coffee.

The Union Jack at Buckingham Palace flies at half-mast in respect for those who lost their lives in the four terrorist bombings in London. Edmond Terakopian/PA

I was then sent to Tavistock Square, where the bus had been bombed. I had high hopes of getting an image because this was in plain sight. Getting there I saw hoards of frustrated media: I knew this wouldn't be easy. Again, the police had covered everything within sight with blue and white cordon tape. I attempted to get into a high-rise hotel, only to be greeted rather rudely by two security men. I was rather chuffed as another four joined them. Obviously they thought two goons weren't enough!

After another hour or so, I had to admit defeat; there was no way I could find an angle. I called the office and was told not to worry, as one of our photographers had managed to get a good shot. "Can you get to Downing Street for Blair in 20 minutes?" I said that it was impossible. I was sent anyway! It was for a picture of the prime minister arriving at Number 10. I missed it. I got another call, "Can you go to Buckingham Palace? The flag's at half mast." Back in the car, off I went.

This was the last image I took. It was a sad way to end London's darkest day. My city had been targeted by terrorists.