On a warm Sunday in late July, Jeff Collins watched his 11-year-old daughter, Hannah, use a rope swing to launch herself into the warm waters of the Edisto River near Charleston, S.C.

It was a day of fun for his family, especially Hannah, who took to the water so much, Collins said, that he called her his “river rat.”

Less than two weeks later, though, Collins held his daughter in her hospital bed, where she lay dying from a rare infection officials say she contracted as she splashed in the water.

The culprit: Naegleria fowleri, the so-called “brain-eating amoeba” that resides mostly in warm recreational waters.

N. fowleri infections are extremely rare, but almost always deadly, according to the Centers for Disease Control and Prevention, which has recorded fewer than 150 U.S. cases since 1962. Ninety-seven percent of people who contract the disease don’t survive — including Hannah, who died Friday, 12 days after she was exposed.

Her family marked her rapid deterioration on a Facebook page.

“Prayers for Hannah Katherine” is filled with happy pictures of the little girl — on a dock near a marshy river, or dressed in a bathing suit, ready to go into a swimming pool.

In one photo, Hannah is wearing a sash, having just been crowned queen of her age division at the Colleton County Rice Festival’s pageant, according to the Charleston Post and Courier.

The written posts, however, provided grimmer images.

“The pressure in the brain has not subsided and is increasing,” the family wrote Wednesday night from the Medical University of South Carolina. “Tonight we will need all your support as extreme measures are being taken in efforts to stop this evil amoeba.”

An update the following morning noted that “the brain pressure is the highest and is threatening her life. Our family is together with her mother, myself, grandparents and family friends. We know you are with us too. Thank you for your continued hopes and prayers and keep them coming.”

Hours later, on Thursday night, came an even darker dispatch: “We have all been waiting and praying for a miracle. However, The Lord has his mysterious plans. There is irreparable brain damage and [the hospital] has done everything in their power. We are now waiting for her to join the Angels in heaven. As you wait with us, please continue to pray.”

The 11-year-old died Friday night, according to a family statement provided to the Beaufort Gazette. (The South Carolina Department of Health and Environmental Control said it could not confirm her death, citing privacy laws.)

“Hannah officially received her angel wings this evening at 10:20 p.m.,” the family’s statement read. “Hannah spent the day surrounded by family and friends, snuggled with her Mom and brother, and listened to prayers and books read by her Grandmother.

“Hannah loved life, her family and friends and, although this is not the outcome we wished for, our sweet girl has joined the angels, and we know she will always be close by, watching over us.”

To contract N. fowleri, known colloquially as “brain-eating amoeba,” water has to shoot up a person’s nose with significant force. That happens when people jump into water that contains the single-celled organism. In one recent case, an Ohio teen rafting during a church trip in North Carolina fell out of the boat into the water at the U.S. National Whitewater Center in Charlotte. She later died from a meningitis infection caused by N. fowleri, health officials said.

As The Post’s Elahe Izadi wrote at the time:

Naegleria fowleri resides in warm freshwater, hot springs and poorly maintained swimming pools. When the single-celled organism enters a person’s body through the nose, it can cause a deadly infection that leads to destruction of brain tissue.

Just 138 people were infected in the United States between 1962 and 2015, according to the CDC.

Lab tests confirmed that Hannah Collins contracted what state health officials called “an extremely rare infection of the brain,” most likely while swimming near Martin’s Landing on the Edisto River in July.

“The Centers for Disease Control and Prevention has confirmed for us today that this individual was exposed to the organism Naegleria fowleri,” state epidemiologist Linda Bell said in a news release last week. “This organism occurs naturally and is all around us and is present in many warm water lakes, rivers and streams, but infection in humans is very rare. In fact, there have been fewer than 40 cases reported nationwide in the past 10 years.”

Hannah’s doctors went to extreme measures to try to save her.

On Tuesday, a courier drove six hours through the night from Orlando to Charleston to deliver a potentially lifesaving drug, according to the Associated Press.

Profunda chief executive Todd MacLaughlan, whose pharmaceutical company makes miltefosine, told the AP that the drug once saved the life of a girl who contracted N. fowleri.

But, MacLaughlan said Wednesday, “time is of the essence.”

There wasn’t enough: On Thursday morning, the family reported that the amoeba was killing Hannah.

A day later, she was dead.

As his daughter was dying, Jeff Collins sat in a jailcell, unable to be with her.

Just before Hannah fell ill, Collins was taken into custody in Colleton County for an unpaid traffic violation, according to Charleston CBS affiliate WCSC. The charge was dropped, but instead of being released, he was transported to Beaufort County, where he had a year-old warrant for not paying child support.

While he was still in custody, officials took him from jail to his daughter’s hospital room. He had 90 minutes with her before she died.

“I was able to lay next to her,” he said in a jailhouse interview with the TV station.  “I didn’t get enough time with her.”

Collins said he learned about his 11-year-old daughter’s death from one of his other children. Would he get out in time to attend Hannah’s funeral?

“I’m just so scared of missing the services,” he told WCSC. “I should be with my family. I am left in the dark.”

Jail officials said Collins was released Monday morning.

His daughter’s funeral will be held Friday at St. Peter’s Catholic Church in Beaufort.

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