decades, for decades now foreign military personnel have been coming to the united states in flight training, it's very significant. because the u.s. has a number of very, u.s. military, large, widespread training ranges across the united states that pilots from other countries, they may not have access to that kind of wide geographic area that they can conduct realistic, in-flight, in the air training. it always starts, of course, with classroom training. what goes on at pensacola. but this is a very well understood, well-known program. it really goes to the question of what was the motivation behind this really terrible attack, brooke? >> right. still too early to say as you point out. barbara starr, thank you so much. we'll continue our special coverage of this shooting at the naval air station pensacola in florida. the number is four dead, eight injured. special coverage continues right after this.