A body found by Coast Guard crews has been identified by family members as one of three missing children who were last heard from on Sunday when they set sail with their father in the Gulf of Mexico.
The children's aunt, Sadie Dilts, told NBC News via telephone the body was that of 17-year-old Rebecca Kimberly. Dilts said that the teen's mother was notified that the body was found 44 miles off the Florida coast wearing a life vest.
The Coast Guard is expected to hold a 10 a.m. press conference to give more details.
The body was spotted by a Coast Guard helicopter at 4:30 p.m. Wednesday, Case said, and sent to local authorities to be identified.
Earlier in the day, six life jackets, four water bottles and at least one tennis shoe were found. A yellow kayak and a green kayak were also discovered Wednesday afternoon, authorities said.
Case said an aircraft spotted the field of debris — "a dire finding" — 33 miles off the coast of Sanibel. A basketball, tarp and propane tank were also found, but the family members and their 29-foot sailboat remain missing.
Case identified the father as 45-year-old Ace Kimberly, who has lived on the boat for about a year with his three children, including sons Roger, 13, and Donald, 15.
The boat, which was anchored in Sarasota, departed Sunday morning for Fort Myers. The cities are about 60 miles apart. The family had planned to meet Kimberly's brother and make repairs to the sailboat, according to the Coast Guard.
Kimberly told his brother Sunday afternoon "he was experiencing rough seas and thunderstorms and that he was worried and wanted his brother on land to send him some weather reports and that's the last that he heard from him," Case said. "The vessel was not in the best of shape."
That afternoon, Kimberly called his brother to say the boat had been caught in squalls and 6-foot surf. He said he was "attempting to survive with his children" off the coast of Englewood, according to the Coast Guard.
His brother contacted the Coast Guard on Tuesday to report them missing, Case said, adding that no distress call was placed.
The Coast Guard activated its Maritime Emergency Response Team out of Fort Myers and continues to search the area by land and sea. The Florida Fish and Wildlife Conservation Commission, Charlotte County Sheriff's Office and Lee County Sheriff's Office are assisting in the search.
"Our thoughts and prayers go out to the family," Case said. "I know this is a super difficult time for them, and we are doing everything we can and throwing everything we have at this search."
Kimberly's brother said the boat had been towing two kayaks and had at least seven life jackets on board, according to Case.
Anyone who enters the Gulf of Mexico is asked to keep a lookout and contact Coast Guard Sector St. Petersburg at 727-824-7506 with any information.
Ari Mason contributed to this report.