From Longman Dictionary of Contemporary Englishhappen to do somethinghappen to do somethingif you happen to do something, you do it by chance I happened to see James in town. → happen
Examples from the Corpus
happen to do something• It happens to all of us.• These bands just happened to be black and popular.• I'm sorry I didn't phone first -- I just happened to be passing and thought I'd drop in.• Justin forgot the map but I happened to have another one in the glove compartment.• We're not related -- we just happen to have the same name.• What will happen to her during the war?• I'd be arrested, Volkov wouldn't know what had happened to me.• She kneels down and gathers me to her, sobbing and shaking in her terror at what might have happened to me.• I happened to see Hannah at the store today.• What happens to the structure of a potato when it is cooked? 2.• Tell me first, what happened to the world when I was in prison.• They don't learn by experience, don't really care what happens to them.