It was on Leno circa 2000-03, don't remember him saying they were killed or not, just that they got confronted by a platooon of heavily armed security troops and an armored vehicle, probably pre-9/11 though. Security was definitely lighter back then, we had a fully manned machinegun nest at my first posting, post 9/11, pre-9/11 this Air Force base I was interning at used to just have window stickers and there wasn't so much as a fence between the free-to-the public museum and the building I worked at, times change and all. Was kinda funny because the rumors all claimed the Roswell UFO was in one of those buildings and the one I worked at had all the windows totally blacked (we were doing really sensitive stuff, but it was light sensitive not secret sensitive) so people would come by, usually stoned, demanding to see the inside because they figured that was the one. It really didn't help that from the entrance you could see this gigantic [but empty] vault door that looked like the entrance to NORAD, nor that without thinking about it when asked who I was I'd say "Oh no, not military just a civilian, physicist, ya'know, space, nuclear, that sort of thing", later I used to go out of my way to jerk their chains since it was the only fun thing to do besides spray our massive cockroach population with liquid nitrogen, which also came in handy whenever the air conditioners broke down (every week). Came up with some really elaborate bullshit stories to egg them on. Good times, good times...