A 74-year-old woman died while snorkeling in the Dry Tortugas National Park, which is in the Gulf of Mexico west of Key West, Florida.
Carol Murrell Maillet of Seattle, Washington, was snorkeling along the fort wall by the beach on Thursday afternoon when family members heard her screaming, Monroe County Sheriff's officials said.
Some nearby people helped bring her to the beach and began CPR. She was then airlifted to the Lower Keys Medical Center on Stock Island in the Florida Keys.
She was not on a guided snorkeling trip, officials said.
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The incident remains under investigation, but foul play is not beleived to be a factor.