What is going on??

I sent my nine year old out to walk the dog and he came back in the house running and locking the door. He said it was about 10 squad cars outside and they told him to get in the house. I don't know what to do now. How will I know when it is safe to go outside or not. We are scared to death over here. Plus my husband is going to be coming home from work soon. I think I am going to call him and let him know what is going on. It has to be something big, if they wanted my son to come inside. I hate things like this. Will keep you posted.. Dana