The Washington Nationals will use opening day to honor people affected by the shooting at the nearby Washington Navy Yard, where a gunman killed 12 people in September.
Four survivors of the shooting will help throw out the first pitch on Friday. And Danielle Knight, whose mother Mary Knight was killed in the shooting, will make the "play ball'' announcement. Flags will be raised by Vice Adm. William Hilarides, the head of the Naval Sea Systems Command. The command's headquarters, the Navy Yard's building 197, were the site of the shooting.
The Nationals are hosting the Atlanta Braves.