helicopter in my neighborhood

Ok, we live near Boeing field so we are in their flight path. I did not think much of the first few minutes of helicopter noise above. But now it has been over a half hour and they are still flying around. I just went through our home, making sure all windows are closed and locked except the back deck which nobody could climb up. Hopefully nothing major is going on, at least it is not being reported yet! I will update if there is any news. Here comes the helicopter again. Wierd.