At least three people killed in helicopter crash near Los Angeles

Heavy rains prompt flash floods and water rescues

First moment of silence takes place in New York for the 25th 9/11 anniversary

Moment of silence held when second plane struck the World Trade Center

Trump escalates trade war with Canada, moving to ban imports of some motorcycles, dairy and alcohol

Officials praise police officers in deadly Minneapolis shooting

Woman killed in Times Square stabbing spree identified as Bank of America exec | NBC New York

LIVE: Steve Kornacki analyzes Massachusetts primary election results | Kornacki Cam | NBC News

Actress Hayden Panettiere dies at 36

What a biological warfare attack could look like

Seattle police chief resigns after festival shooting

More Americans moving to the Midwest amid nationwide affordability crisis