For some unknown reason, she cut her eyes to his feet.

But instead, for reasons still unknown to us, something had gone wrong.

She had been home from work earlier in the day, having taken the afternoon off for some unknown reason.

They might have come for reasons quite unknown to us.

The project was put on hold for an unknown reason in March 2010.

The team did not play in 2012 for unknown reasons.

The games did not continue into 2012 for unknown reasons.

Now, for some reason unknown to her, she no longer felt so.

Or whether for some unknown reason she just didn't want me to go.

Her father seems to have left the family for unknown reasons by 1930.