Naya Rivera is missing after taking a boat ride with her 4-year-old son in Lake Piru in the Los Padres National Forest in Ventura County, California, on Wednesday, the Ventura County Sheriff's Department has confirmed.The Sheriff's Department told NBCLA that the actress and her son, Josey, rented a boat at around 1 p.m.Approximately three hours later, another boater discovered her young son in the boat by himself.