Braxton Williams, 6, and his 5-year-old sister Bri'ya Williams were last seen playing in the front yard of their mobile home in Jacksonville, Florida, Sunday morning. The young siblings disappeared, prompting their family to report them missing that afternoon after searching and being unable to find them, ABC News reports. The Florida Department of Law Enforcement has now issued an Amber Alert for the children, referring to them as "endangered."
"We're not going to spare any expense, the search will continue throughout the night as it's going right now until we find these children," the Jacksonville Sheriff's Office's public information officer said at a press conference Sunday night. "We're searching ponds, we're searching trash cans, we're searching everything." Braxton has Asperger syndrome but does communicate with people, authorities say. "We haven’t slept. We haven’t eaten. We are worried about our babies," the children's grandmother tells Action News Jax, noting that she has never known the siblings to go into a wooded area near their home. "We need a lot of prayers." (Read more missing child stories.)