YouTube headquarters shooting: A 38-year-old gunwoman opens fire at YouTube Headquarters in San Bruno, California, injuring three people before committing suicide.

On April 3, 2018, at approximately 12:46 p.m. PDT, a shooting occurred at the headquarters of the American video-sharing website YouTube in San Bruno, California. The shooter was identified as 38-year-old Nasim Najafi Aghdam, an Iranian-American woman, who entered through an exterior parking garage, approached an outdoor patio, and opened fire with a Smith & Wesson 9 mm semi-automatic pistol. Aghdam wounded three people, one of them critically, before killing herself with her own firearm. She was just two days short of what would have been her 39th birthday.

San Bruno is a city in San Mateo County, California, United States, incorporated in 1914. The population was 43,908 at the 2020 United States census. The city is between South San Francisco and Millbrae, adjacent to San Francisco International Airport and Golden Gate National Cemetery; it is approximately 12 miles (19 km) south of Downtown San Francisco.

April 3 is the 93rd day of the year in the Gregorian calendar; 272 days remain until the end of the year.