If you haven't seen the movie yet, then I suggest you read no further. For those who did see this movie, what exactly killed the Aliens? It confused me. Any info would be appreciated.

I think it was a virus, remember when those aliens came into that basement? I think they picked up a virus or could have been when they had the people in inside those tripods and was sucking them up into that chamber this may have allso contributed to the virus, even though its not clear at the end of the movie. the answer may be in the beginning of the movie where morgan freeman is narating it.