A man opened fire just after his son's baseball game, killing his estranged wife and the 10-year-old boy as players and parents fled for cover. The man later killed himself, authorities said.
The woman, 31, was watching the game from her car at a St. Louis park when she spotted her husband. She yelled for her son, but the gunman began shooting before they could escape, police said.
The man killed his wife, then turned the gun on his son, St. Louis Police Chief Joe Mokwa said. No one else at the park was injured.
Police later found the man, 34, dead from a self-inflicted gunshot wound to the head.