Today started off like any busy Monday morning, and for a lot of office staff who are commuting to work - that means a stop-off at a favourite cafe for a quick take-away coffee on their way to work.
For those who work in or near Martin Place the Lindt cafe is an obvious choice for them.
But this morning was to be different. What started as a quick trip in the doors of the cafe was to turn out to be a siege led by a lone gunman.
News broke of the cafe drama at around 10.15am local time through an alert system that operates in the city.
But the response of the police has been incredible and very reassuring.
There is an alert system here in Sydney which is very efficient, and I've seen it tested a few times before, but I didn't think I'd ever see it used in a real situation.
If an incident happens signs that are placed around the city light up with messages, and loudspeakers issue voice messages to everyone in the streets and in train stations and transport hubs.
When the alert happened this morning the signs said there was an emergency in the Central Business District and everyone was to avoid the area, and similar messages were broadcast through the loudspeakers.
Immediately there was nervousness as everybody wondered what was going on, but between the alert system and the media it quickly emerged that there was a siege in the cafe.
The general consensus here is that the gunman deliberately chose this cafe because it is across the road from the offices of a large TV network, and there would be maximum publicity.
People were relieved when first two hostages were seen escaping.
Then three more ran out and people thought it might be coming to an end.
We weren't sure if those hostages had been released or made their own escape, but at least they will be able to give police some detailed information about what is going on inside the cafe and how well armed the gunman is.
A lot of the nervousness is because there have been reports of bombs planted around the city and nobody knows if it is true or not.
But maybe the escaped hostages can bring some clarity to that claim.
The police have been on their guard here since they apprehended a number of terror suspects in recent months who claimed they were going to capture ordinary citizens and take them hostage.
The area around Martin Place was mentioned and they said they were going to behead people on camera.
Naturally everyone was very worried about it at the time so the police have been vigilant and I guess Australians were expecting some form of attack to come and everyone was trying to be prepared for that.
Now that we are heading into the night we are not sure how long the siege might last.
We know the gunman has issued demands through some of his hostages who he forced to telephone a television station, but the details of those demands are being kept under wraps for the moment.
I've been making my way home from work and I've passed two train stations and I can see police everywhere but in a very calm and organised way.
All the shopping centres and cinemas, and places where large numbers of people gather, all seem to have closed as part of the alert response.
The big banks have also reacted in a similar way, and many workers have been told not to leave their offices.
It is summertime here but in the run-up to Christmas the streets have all been full of shoppers, but now that area of the city has been completely cordoned off.
All eyes will be on the TV for the night to see what the outcome will be, and we don't know yet who is in the cafe or if any of them are Irish.
Some of the Irish bars and other businesses in the district are now shut down because they are within the cordon.