Will I get fined for going through a zebra crossing whilst people waited?

I was driving in an area I’ve never been to before and it was pretty busy. It was a shopping retail area and I was driving to exit the place, there was a lot of traffic infront, behind and on the opposite direction. There was a car infront of me and one to the side, meaning I didn’t see a zebra crossing (it also didn’t have lights) so by the time I seen it, I was practically on top of it since the other car went through it while people were standing next to it. If I had slammed the breaks on to stop, the car behind would have gone into the back of us pushing into the traffic of pedestrians. There was no one on the road, just at the sides and obviously I felt awful when I went past it, but hard to do anything when I couldn’t see it and nothing showed it was a crossing and if I stopped it would have been more of a disaster. What’s the rules for this?