Friend vs. Friend

OK so I have a friend who is a girl and her little brother and my little brother are friends as well. The only problem with that is our little brothers are ALWAYS getting in trouble together.
My friend and I talk about our brothers and the stupid things they do to get in trouble. We usually laugh about it and are just like "Oh our little brother." The only real "rule" we had was that we never actually talked about this subject with anyone else. it is exclusively out conversation everytime it is brought up.

but a couple nights ago our siblings were out doing drugs at a local elementary school and the cops showed up.
In the end her brother got arrested and spent the night in jail.

I found out a day later and I felt like calling and talking to my friend about it.

but when I said to her "You're brother went to jail last night" all I heard was silence and she started crying and hung up on me.
She had a nervous break down. This reaction stunned me

In the past when we talked about our bros antics I never got this kind of reaction and I wasn't expecting it.

Later that night i called and talked to her brother and he said that he understood why I told her, and that he understood why I felt the need to tell her based on our relationship.

But now i can't help but feel absolutely terrible, like I'm to blame for something.

I'm afraid that my actions will be taken the wrong way and that my intentions are in question.
I think that she might think I was just calling to gossip.

I am deathly afraid of losing a friendship over something like this. PLEASE help me out.