The other day was a really good example of what I'm trying to describe.
I was standing in a long line waiting for a bus when a fire truck pulled up almost right in front of the station. Whatever it was was so bad that they were re-directing traffic on an alternate route around the problem. It turned out to be a car accident spread across 3 lanes of traffic with what looked like at least one serious injury.
We all stood there for 5-10 minutes, half of us being able to see what was happening. Then our bus came and we all got onto and filled the bus up to capacity and headed off to work.
What floored me is how no-one talked to each other about what we'd seen; while we were waiting for the bus and afterwards while we were all crammed onto the bus.
This is a very easy situation to be friendly and get to know the people around you. All you have to do is turn to the person beside you and start talking about what you're seeing. How bad it looks, pointing out things you notice (eg. that over there looks like it could be bad), how shocked you feel, sad you feel for the people involved, what the consequences could be.
The important thing about conversation, and this situation is a good example, is that there can be lulls in the conversation. For example, you both may share a few comments on what you're seeing. Then you may both stand there and quietly watch it. When someone has something else to add they can just pipe up and say it; the conversation can move and/or grow organically from there. It may stay on topic, it may change topics to related stuff, there may be another lull, etc..
And there's nothing saying that the conversations could not have kept going inside the bus. Or that, once on the bus, you continued the conversation with other people who had seen it and get fresh perspectives.
Also, in this kind of situation, where whatever the topic is is in the immediate vicinity & shared among other people, it's ok to pipe up and join in in a conversation with the people beside you.
The important thing is is that you shared with the people around you (i.e. your community) the experience. It's things like this that break the isolation and will significantly reduce the feeling of alienation and loneliness that so many people feel the effects of.
