I guess this is a coincidence.

It was completely coincidental.

I don't think it's more than coincidence.

I think it's just a coincidence.

Look, what an amazing coincidence! Tom has the same fingerprints as me.

It was no coincidence that all the stores closed earlier today.

Lunch is at 12:00 to coincide with the Technical Group.

I don't think it's a coincidence that Tom and Mary are both here.

Was that a coincidence?

It's hard to believe that's a coincidence.