We had been getting e-mails about it from the University for weeks in advance, but none of us knew quite what to expect.

The G-20 summit, the leaders of the 20 richest nations in the world, were coming to Pittsburgh on the 24-25th September.

I remember a taxi driver in early August telling me how they were going to block off the whole city, and with him being quite a loud mouth, I took his comments with a pinch of salt. So when I saw thousands of special force policeman, SWAT teams and soldiers rolling into town two days before the summit started....I finally sat up and took notice!

The whole of downtown Pittsburgh became a ghost town overnight. A bustling metropolis was shut down and became eerily quiet, as the buzzing of helicopters overhead was the only sound that was distinctive. The leaders meet at two locations, one at Lawrence convention center downtown. The over location was Phipps conservatory, something similar to Kew Gardens. This conservatory happened to me less than half a mile from where I live, so I was right in the middle of the mayhem to come.

The big concern was the protesters, as previous summit's in London and Seattle had turned violent. The anarchists and other hardcore groups roamed the streets with black masks over their faces, they marched towards the "no go zones" with no fear. I was sat in my room watching this on CNN, and reading about it on the BBC website. I then glanced out of my living room window to verify exactly what I was seeing on TV was going on outside.

Evidently, this was the case.

The first night of rioting was by far the most violent, with Police reacting to vandalism from the protesters along their march from Downtown Pittsburgh to The Phipps Observatory in Oakland, about 2 miles.

Riot police were roaming up and down 5th avenue, launching gas canisters into crowds of fleeing protesters. These protesters had caused damaged to many local businesses the night before, smashing windows and causing havoc on the streets of the Oakland district of Pittsburgh, my home for the last 2 and a half years.

The riot police were in no mood to let this happen again, they moved in to assert their power on the 2nd night by 11pm, and the scenes outside were evident of something in Baghdad or Belgrade, yet it was happening in Pittsburgh!!!

Armoured vehicles roared up and down, with hundreds of riot police in tow, protesters regrouped and tried to run towards the police again and again. They could not really harm the police, yet they were a nuisance. Local TV were reporting live from the scene, the iconic cathedral of learning, and showed my building as me and my room mate were hanging out the window trying to get the best vantage point.

In a matter of an hour or so, the 2nd night of riots were over. I had ventured out with a few of my team mates earlier to see what had been going on, but we quickly moved on as the anarchists groups didn't quite take to us being there and we felt someone outsiders, dangerously on the inside. Riot police surrounded us everywhere and repeatedly they announced over loud speakers for the crowd to "disperse immediately, or you will face appropriate force."

We got the message, and watched the rest from out living room and TV sets.

The talks between Obama, Brown and co. were successful, but the violence and the shutdown of the city were the big stories for Pittsburgher's.

The world came to Pittsburgh on the 24-25th September, 2009. But Pittsburgh couldn't really welcome it. There were 3 checkpoint sites across the city were only people with special passes could pass through, each a mile from the center of downtown. It was like a military base, except this was usually a thriving, bustling city.

It was a success, and an exciting time to be in the middle of it all. It's something I will always look back on.

But it nags at me that although there were, and still are, billboards everywhere stating "Pittsburgh welcomes the world, 24-25th September 09," this wasn't actually the case.

The real Pittsburgh was never really present, and I'm sure it never made a lasting impression on any of the world leaders.

Which is a shame, as there is lots on offer in the "steel city" that I have grown to love.

Visit Pittsburgh, I promise you will be welcomed warmly, whoever you are.