Federal investigators are joining San Antonio police in the search for missing 3-year-old Lina Sadar Khil, who was last seen at a playground near her apartment complex on Monday evening. READ MORE: https://abcn.ws/3H6kSic SUBSCRIBE to GMA's YouTube page: https://bit.ly/2Zq0dU5 VISIT GMA's homepage: https://www.goodmorningamerica.com SIGN UP to get the daily GMA Wake-Up Newsletter: https://gma.abc/2Vzcd5j FOLLOW GMA: TikTok: https://tiktok.com/@gma Facebook: https://facebook.com/GoodMorningAmerica Twitter: https://twitter.com/gma Instagram: https://instagram.com/GoodMorningAmerica WATCH full episodes: https://abc.go.com/shows/good-morning-america https://hulu.tv/2YnifTH #GMA #SanAntonio #LinaSadarKhil #AmberAlertamb #Texas