Complications may cause a miscarriage or spontaneous abortion to occur.

I didn't realize that I'd cause it to occur immediately.

Can you explain what caused this to occur?

He says there's a magnetic flux about the earth which causes like events to occur simultaneously or in sequence.

This causes a form of sonic boom to occur.

Doctors do not know what causes a heart attack to occur suddenly when it takes years for the underlying damage to develop.

I fear that some error on my part caused this to occur.

There was much speculation and research after these shootings as to what caused them to occur.

No one knows exactly what causes tics to occur.

Indeed, to do so might be in itself, or cause to occur, a failure of leadership.