For the most part, they are not in any contact with the public. The Sailors and Marines are on the ships. The Marines at the Embassy's are inside the gates, locked and loaded ready to protect all American interest abroad. All the places we have ground bases are more or less under lock down to a degree. No one enters without proper credentials, and no one leaves without specific instructions and guidelines. This is how things are more or less handled.
When the OK city thing went down, everyone was called to base, all the birds were prepped for emergency flights, weapons were on stand by to be checked out at the armory.
A lot of the non essential communications are cut. We had to do this primarily because the Russians and Chinese had fishing boats outside the East Coast in the Camp Lejune/New River/Cherry Point area that were used to listen in on phone conversations.
Dont worry. Your family is safe. Things like this are gone over in back rooms every day in preparation for such attacks.