I was reading an old story:
"Inspector Diane Groomes of the 3rd Police District, who was on the scene early today, said members of the group also broke out the windows of some restaurants and at least one bank in the 1700 and 1800 blocks of Columbia Road, a popular strip of restaurants and clubs."
"Broke the windows" is understandable enough for me. But what does "out" add to "broke"?
I find it unusual too. "Broke" or "smashed" would have been sufficient. I also think it's odd that they chose "broke out". To me, in order to "break something out" you have to be in somewhere in the first place. I think the people who smashed those windows were outside the restaurants and the bank and the windows were in fact "broken in" (if anything), with the glass ending up inside the building.
I would use "break out" in the following contexts:
1) I won a gold medal. Break out the champagne! = meaning "Get the champagne out and pop the cork!"
2) I am going to break out of prison = I am going to escape from prison.
3) If I eat more chocolate, I'll break out in spots = spots will appear on my face (if you suddenly get spots (pimples in AmE), it's described as a "breakout".)