Preventible by childhood vaccines. Why arent more children getting it . Nightly news starts right now. From nbc news World Headquarters in new york, this is nightly news with lester holt. Good evening. For a second day in a row we have been confronted by the graphic images shared across social media of a man dying after being shot by police under questionable circumstances. The latest was streamed live over facebook. It showed a bloody scene inside a car, and it was calmly narrated by the fiancee of the driver just after he was shot by a Police Officer during a traffic stop in st. Paul, minnesota. The video has provoked public outrage and protests. But official answers as to what led up to the shooting have been slow to come. Tonight, however, we have pieced together some of the critical details. Nbcs blake mccoy has the latest. Reporter moments after Philando Castile is shot by police they killed my boyfriend. Reporter his fiancee, diamond reynolds, hits record, broadcasting live to f