eastern ukraine, russian border, embroiled in fighting between ukrainian forces and pro-russian separatists. their relationship with the russian military has been murky for a very long while now and that is part of figuring out what happens next here. the crash site is in an area that is under rebel control. the rebels are denying any responsibility for the crash. as are the russians. how much of an investigation can be done in what is realistically a war zone? who will do that investigation? what do we still expect to be able to find out about how this happened, where it originated from, and who did it? joining us now, longtime nbc news aviation correspondent, robert hager, mr. hager has been an on the ground reporter in passenger jet disasters including pan am over lockerbie. mr. hager, thank you for being with us tonight. >> sure, rachel. by the way, i covered both the soviet shoot-down of the korean passenger plane, as well as the iranian airbus that got shot down. >> when you look back at the history of these and put them on